T-Mobile Corporate Responsibility Report

ALL IN ALL IN ALL IN ALL IN IN OUR RELENTLESS PURSUIT OF PROGRESS 2021 Corporate Responsibility Report T-Mobile US, Inc.

2021 CORPORATE RESPONSIBILITY REPORT OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT WHAT’S INSIDE Connect with T-Mobile This report is aligned to the world’s most widely used standard for sustainability reporting—the Global Reporting Initiative (GRI) Standards, as well as Sustainability Accounting Standards Board (SASB) Standards for our industry. It covers the operations and activities of T-Mobile US, Inc. for the calendar year 2021 (January 1 to December 31) unless otherwise noted. Find out more about the numbers and small print . 3 Our Company 3 CEO Statement 4 About T-Mobile 6 ESG Approach 10 ESG and Industry Trends 11 5G Innovation 13 Our Governance 14 2021 Highlights 15 Ethical Business Practices 18 Corporate Governance 19 Business Continuity 20 Data Privacy 22 Cybersecurity 23 Responsible Supply Chain 26 Our People 27 2021 Highlights 28 Our Culture 29 Diversity, Equity, and Inclusion 35 Employee Engagement, Learning, and Development 38 Health, Safety, and Wellness 40 Our Communities 41 2021 Highlights 42 Digital Equity 47 Philanthropy 50 Disaster Relief 52 The Environment 53 2021 Highlights 54 Climate Change 56 Energy Management 58 Waste and Recycling 59 Product Lifecycle Management 61 Natural Resources Management 63 The Numbers and Small Print 65 Notes About This Report 66 ESG Data 70 T-Mobile Material Topic Definitions 71 GRI Index 88 SASB Index 26 Celebrating our people at T-Mobile 52 Caring for our environment 40 4040 Givin Giving baGiving ba g back ck tck t to oo the co the communit the communit mmunity yy

CEO Statement THE ENVIRONMENT THE NUMBERS AND SMALL PRINT OUR GOVE RNANCE OUR COMMU NITIES OUR PEOPL E 2021 CORPORATE RESPONSIBILITY REPORT 3 OUR COMPANY A WORD FROM OUR CEO, MIKE T-Mobile’s mission is to be the best in the world at connecting customers to their world. It is at the heart of who we are, driving our obsession to enable more people in more places to have access to the connectivity shaping virtually all aspects of modern life —and making it our priority to not leave anyone behind. It goes without saying that the last few years have been challenging—for our customers, our employees, and society as a whole. And, when I look ahead, I see economic, political, and societal tides that will continue to test our resolve and spirit as a company, country, and as human beings living together in our shared world. But it’s also during these times that I’m more convinced about our mission than ever—because it’s our need for connection—to one another and to our community— that makes us human. And that’s what T-Mobile is all about—we connect people. That’s why we are investing so heavily to further ext end our unrivaled 5G leadership with our transformative network. It’s also why we are so proud of, and committed to, Project 10Million, our landmark five-year initiative to provide free or heavily subsidized connectivity to under-connected households with school-aged children across the U.S. As w e enter a new era of Un-carrier, we’re committed to bei ng an even greater force for good in wireless and the world in which we live. We know that we can’t be the best at connecting customers to their world without being prepared to change our industry, and the world, for the better. We didn’t earn our Un-carrier stripes by shying away from doing the right thing, and it’s why T-Mobile has pledged to use our expanded network, scale, and resources to deliver 5G for All and create a connected world where everyone can thrive. MIKE SIEVERT CEO T-Mobile US, Inc. @MikeSievert However, none of this comes to life without our employees, the heart and soul of our company and the key to our success. They are the passionate champions for our customers. They are diverse and engaged representatives of our communities. And it’s our employees who are the foundation of our iconic and vibrant Magenta culture. Two years after our historic merger with Sprint, we continue to invest in the growth and well-being of our employees and the health of our culture. Foundational to this work is our long-standing commitment to diversity, equity, and inclusion. I am proud of the open, diverse, and “be you” culture that we foster at T-Mobile. And we are constantly striving to do more. This work remains a focus as we continue on our path to lead by example, put people first, and provide the best opportunities, within the best culture, to everyone that works at T-Mobile. Finally, being in the business of connecting people comes with great responsibility. We are resolute in our commitment to operate responsibly, with integrity, and with a focus on the well-being of our communities and planet. I’m immensely proud that T-Mobile sources renewable energy equivalent to 100% of our electricity usage—a first for our industry. And in 2021 alone, we invested over $1.8B in order to strengthen our communities through funding and in-kind support.

Our Story

About T-Mobile UNSTOPPABLE UN-CARRIER Today, we’re leading the U.S. wireless industry with America’s ONLY nationwide stand-alone 5G network, unmatched value, and unwavering customer love. As we enter a new era of Un-carrier, we are continuing to focus on doing what’s right for our customers and building a more sustainable, inclusive future for all. To learn more about T-Mobile’s economic con tribution and business strategy, view our Annual Report . 108.7M customers Including 646,000 High Speed Internet customers (as of December 31, 2021) THE ENVIRONMENT THE NUMBERS AND SMALL PRINT OUR GOVE RNANCE OUR COMMU NITIES OUR PEOPL E 2021 CORPORATE RESPONSIBILITY REPORT 4 OUR COMPANY * Fastest based on median, overall combined 5G speeds according to analysis by Ookla® of Speedtest Intelligence® data 5G download speeds for Q4 2021. Ookla trademarks used under license and reprinted with permission. ** Based on analysis by T-Mobile of Speedtest Intelligence® data from Ookla® U.S. median 5G T-Mobile speed tests from cities with 2.5GHz compared to mobile Wi-Fi results for Q4 2021. Ookla® trademarks used under license and reprinted with permission. America’s Largest 5G Network Our Extended Range 5G covers 310 million people or 94% of the U.S. population (as of December 31, 2021) America’s Fastest 5G Network* Delivering speeds faster than Wi-Fi to more people than any other wireless provider** Providing services, devices, and accessories across our flagship brand T-Mobile and prepaid brand Metro by T-Mobile Headquartered in Bellevue, WA & Overland Park, KS with corporate offices in Frisco, TX; Atlanta, GA; Reston, VA; and other locations

WHAT MAKES US DIFFERENT? About T-Mobile Continued OUR VALUES BE BEST IN THE WORLD AT CONNECTING CUSTOMERS TO THEIR WORLD OUR MISSION OUR VISION IN CUSTOMER CHOICE IN CUSTOMERS’ HEARTS # 1 Do It the Right Way, Always One Team, Together Love Our Customers Dream BIG and Deliver We Won’t STOP THE ENVIRONMENT THE NUMBERS AND SMALL PRINT OUR GOVERNANCE OUR COMMUNITIES OUR PEOPLE 2021 CORPORATE RESPONSIBILITY REPORT 5 OUR COMPANY We don’t just do customer service. We do customer love. Simply put, their “happy” is our “happy.” We do the right thing. For our customers, our shareholders, society and each other. Every time. We celebrate each other. Listen to and empower each other. INCLUDE each other. We value what each person brings. That’s how we win. We aim high. We step out. Take smart risks, and own our results. We act like owners because we ARE owners. We are relentless. Striving. Never complacent. We find a way, busting down barriers. We don’t wait for change, we make it.

ESG Approach How We Drive Impact Our business has a big impact on the way society lives, works, learns, and engages with the world. That’s why our environmental, social, and governance (ESG) approach is guided by a simple yet bold aspiration to create a connected world where everyone can thrive. That means responsibly operating our business to create long-term value for our most important stakeholders, while never losing sight of our opportunity to leverage our size, scale, technology, and the power of our brand to be a force for good. We actively manage and address a range of ESG matters—from providing equitable access to connectivity, to championing diversity, equity, and inclusion in our workforce and society, and sustainably managing our environmental footprint as we continue to grow our business. Fundamental to this work is our ongoing commitment to responsible business practices that promote accountability, transparency, and ethical conduct. THE ELEMENTS OF OUR ESG APPROACH Equitable Opportunities We are loud and proud champions and advocates of diversity, equity, and inclusion —within our walls and out in the world. We are a stronger company when every employee feels valued for who they are and equipped to constantly innovate and offer the best for our customers. That’s why we’re committed to providing equitable opportunities for all. For more information visit p.26 Digital Empowerment We connect people. It’s our mission and our passion, because we fundamentally believe that access to connectivity and the digital skills to navigate our world have become two of the most important differentiators of societal equity today. That’s why we’re empowering people with essential connections, tools, and skills needed to succeed in today’s digital world. For more information visit p.39 Thriving Planet We recognize that our innovative products and services that provide connectivity to our customers also have an impact on the environment. By taking bold steps now to reduce our environmental footprint, we can help create a more sustainable future for everyone. That’s why we’re mobilizing our resources, people, and partnerships to support a thriving planet. For more information visit p.52 THE ENVIRONMENT THE NUMBERS AND SMALL PRINT OUR GOVERNANCE OUR COMMUNITIES OUR PEOPLE 2021 CORPORATE RESPONSIBILITY REPORT 6 OUR COMPANY Responsible Business Underpinning our strategic areas of focus is our commitment to doing things the right way, always. That means being uncompromising in our ethical code and upholding strong corporate governance policies and practices that help us earn and keep the trust of our customers, employees, and the communities we serve. Winning is important to us—but how we get there matters. For more information visit p.13

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ESG Oversight Oversight of our progress on ESG issues that are important to our business and our stakeholders occurs at the highest levels of our company. This encourages stronger consideration of ESG matters when making decisions and improves cross-functional collaboration. ESG Approach Continued OUR GOVERNANCE STRUCTURE T-Mobile Board of Directors Oversees and reviews management activities and advises on long-term and strategic issues, with a view to enhancing the long-term value of T-Mobile. Outside of the regular cadence of briefings, periodically receives additional updates on enterprise risk, cybersecurity, and other notable ESG matters from management and Board committees. Audit Committee Assists the Board in oversight of T-Mobile’s risk assessment, risk management policies, and compliance with T-Mobile’s Code of Ethics. Receives enterprise risk updates four times a year, including on risks relating to network resilience and business continuity, cybersecurity, and data privacy. Receives an annual fraud risk assessment. Nominating and Corporate Governance Committee Provides oversight of T-Mobile’s compliance and ethics program, cybersecurity, data privacy, sustainability, and corporate social responsibility initiatives. Receives quarterly briefings on key ESG topics, emerging trends, and progress, including cybersecurity and infrastructure security. Receives an annual update on political contributions and charitable spending. Executive Management T-Mobile executives provide oversight of critical ESG issues, risks, and progress on initiatives. Key executives provide updates to the Audit Committee and the Nominating and Corporate Governance Committee. Executives co-lead and serve on internal cross-functional committees to drive enterprise- wide alignment and to provide strategic guidance and effective oversight of key issues. Key Cross-Functional Executive Management Committees Enterprise Risk and Compliance Committee • Information Security and Privacy Council Equity In Action Leadership Task Force • Sustainability Steering Committee • Charitable Giving Steering Committee • Data Privacy Steering Committee and Security Steering Committee DE&I Internal Oversight Committee THE ENVIRONMENT THE NUMBERS AND SMALL PRINT OUR GOVERNANCE OUR COMMUNITIES OUR PEOPLE 2021 CORPORATE RESPONSIBILITY REPORT 7 OUR COMPANY

ESG Approach Continued Stakeholder Engagement As the Un-carrier, we changed the wireless industry by listening and responding to our customers. We take the same approach to inform our ESG strategy by understanding what is important to our key stakeholders—customers, employees, community partners, suppliers, and shareholders. By gathering input through a variety of formal and informal channels, we can better understand what our stakeholders care about and where they see us having the greatest impact and influence. This helps better align our actions with the priorities most relevant for our industry and our business. ESG MATERIALITY ASSESSMENT One of the most important tools we use to listen to our stakeholders is a third-party ESG materiality assessment. Conducted every couple of years, this assessment directly asks our leaders, employees, customers, and other key stakeholders to rank the ESG issues they care about and tell us what topics they think are most important for T-Mobile to address. See our most recent ESG materiality assessment . SHAREHOLDER ENGAGEMENT T-Mobile believes in frequent, consistent, and transparent communication with shareholders. Our senior management and investor relations team engage extensively and regularly with shareholders on topics that include ESG matters. Engagement takes place through one-on-one conversations and group meetings, major industry conferences, quarterly earnings, and through T-Mobile’s first Analyst Day, which we hosted in March 2021. THE ENVIRONMENT THE NUMBERS AND SMALL PRINT OUR GOVERNANCE OUR COMMUNITIES OUR PEOPLE 2021 CORPORATE RESPONSIBILITY REPORT 8 OUR COMPANY EXTERNAL DIVERSITY AND INCLUSION COUNCIL T-Mobile partners with our External Diversity and Inclusion Council to help guide and support our Equity In Action (EIA) objectives. The Council includes leaders from the National Urban League, League of United Latin American Citizens, National Action Network, Unidos U.S., OCA-Asian-Pacific American Advocates, Asian Americans Advancing Justice, Human Rights Campaign, National Organization on Disability, National Association for the Advancement of Colored People, National Diversity Coalition, and Multicultural Media, Telecom and Internet Council. EMPLOYEE RESOURCE GROUPS AND LOCAL DE&I CHAPTERS The passionate and dedicated volunteer leaders of our Employee Resource Groups (ERGs) identify diversity, equity, and inclusion (DE&I) opportunities where our company can make the biggest impact. T-Mobile has six ERGs with four sub-affinity groups and 50+ local DE&I Chapters around the country. In addition to hosting events, these groups provide a forum for ongoing dialogue and feedback on important issues to ensure that diverse voices across the company are heard. COMMUNITY ENGAGEMENT Community engagement and feedback is important to our business. That’s why we work to foster strong relations with local communities and external partners so that we’re informed of critical issues impacting our customers, company, and industry. By consulting with local officials, community partners, and industry associations about our business and potential impact, we can incorporate feedback into key initiatives and champion change where it’s needed most.

ESG Materiality Assessment T-Mobile’s most recent ESG materiality assessment took place in 2021 after our merger with Sprint to ensure a timely and full picture of the evolving ESG landscape. The assessment included an analysis of emerging ESG trends and standards, survey responses from employees and customers, and in-depth interviews with internal and external stakeholders, including investors, suppliers, community partners, and advocacy organizations. This allowed us to identify and prioritize the most significant ESG issues for our business and stakeholders. Governance topics such as digital privacy and security and ethical business practices scored high. Critical areas of social impact, like digital equity, employee diversity and inclusion, human rights, and health, safety, and wellness, rose to the top. Finally, climate change and waste and recycling were among the top environmental issues. ESG Approach Continued The Key Findings The ESG topics identified as most significant in the assessment are listed below in order of their relevance in the materiality matrix i . Details of these topics are covered in the following sections: GOVERNANCE 1. Digital security and privacy 2. Ethical business practices 3. Human rights 4. Open internet and competitive behavior 5. Business continuity and network resilience 6. Sustainable and responsible supply chain 7. Responsible marketing 8. Corporate governance 9. Economic contribution 10. Partnerships and collaboration RESPONSIBLE BUSINESS SOCIAL 1. Health, wellness, and safety 2. Digital equity 3. Employee diversity (equity and inclusion) 4. Responsible use of products and services 5. Philanthropy and community engagement EQUITABLE OPPORTUNITIES DIGITAL EMPOWERMENT ENVIRONMENTAL 1. Greenhouse gas emissions and climate change 2. Waste and recycling 3. Natural resources management and conservation 4. Energy management 5. Product lifecycle management THRIVING PLANET THE ENVIRONMENT THE NUMBERS AND SMALL PRINT OUR GOVERNANCE OUR COMMUNITIES OUR PEOPLE 2021 CORPORATE RESPONSIBILITY REPORT 9 OUR COMPANY See our complete list of ESG topics and definitions . The information disclosed on these ESG topics in this report should not be considered a characterization of the materiality or financial impact of such topics. For more information, please see Notes About This Report . i T-Mobile, 2020. 2020 Corporate Responsibility Report. T-Mobile, p.51.

ESG and Industry Trends Anticipating Change in a Fast-Moving World Both our industry and our world are moving and changing quickly. T-Mobile is positioned at the forefront of technologies driving change, including the transformational capabilities of 5G. Through innovation, investment, and a constant eye on emerging trends, we can better deliver on both the current and future needs of our customers, while never losing sight of our commitment to responsible business practices. These are some of the key ESG and industry trends on our radar and how we are tackling them. CUSTOMER SATISFACTION IS GROWING EVER MORE IMPORTANT In an era of 24/7 connectivity, delivering on customer expectations is more important than ever. That’s why the customer-obsessed heroes who make up Team Magenta are our most powerful differentiator. Because of their dedication to our customer-first approach, T-Mobile is consistently recognized for providing amazing customer service across our flagship brand, T-Mobile, and our prepaid brand, Metro by T-Mobile. Find out more about what makes Team Magenta and our culture different in our Culture section . IT TAKES PUBLIC AND PRIVATE SUPPORT TO ADEQUATELY ADDRESS THE DIGITAL DIVIDE Internet infrastructure is an essential part of a digitally inclusive society, but it’s just one piece of the puzzle. Affordability, access, and digital proficiency are all important factors that require action from both the private sector and government. As the U.S. takes steps to close the digital divide, including a $65 billion investment to improve broadband infrastructure through the American Jobs Plan, at T-Mobile, we’re continuing our critical efforts to support digital equity through our five-year $10.7B Project 10Million commitment. Find out more about how T-Mobile is supporting digital inclusion and empowerment and connecting millions of students who lack home internet through Project 10Million . EVOLVING EMPLOYEE EXPECTATIONS REDEFINE PRIORITIES FOR COMPANIES Not surprisingly, the last two years have had a profound impact on employee health, well-being, and engagement. Navigating the pandemic and resulting personal, family, and professional stressors have impacted everything from employee health and wellness to workplace expectations. At T-Mobile we’ve always prioritized our employees and take the time to listen to their feedback on a range of topics, including workplace flexibility, health and safety, and career development. We have doubled-down on opportunities for career growth and increased mental health offerings, among other investments. Find out more about how we enable Team Magenta to thrive through DE&I initiatives and learning and career development . TELECOMMUNICATION COMPANIES PRIORITIZING MORE EFFICIENT AND SUSTAINABLE ENERGY Telcos in the U.S. and overseas are accelerating their actions on climate and sustainability. An important area of focus is around sustainable energy management, which includes shifting to renewable sources of power, adopting energy-efficient measures and new technology available for 5G networks, and developing services that allow customers to reduce their carbon footprint, such as Work From Anywhere and Internet of Things (IoT) solutions, fleet management, and device recycling. Find out more about our sustainable energy management and device recycling work . 5G INNOVATION IS OPENING UP NEW ECONOMIC OPPORTUNITIES 5G’s faster speeds and greater bandwidth are powering incredible innovation potential and economic gains. In fact, it is forecasted that 5G’s impact on the global economy will count for more than $1.3 trillion by 2030 ii . Not only can the power of 5G help companies grow their businesses, but it can also fundamentally change the way some industries operate. We can expect to see transformations fueled by 5G in manufacturing, healthcare, financial services, utilities, and of course, consumer and media applications. Find out more about how T-Mobile is responding and contributing to 5G-powered innovation in the next section. THE ENVIRONMENT THE NUMBERS AND SMALL PRINT OUR GOVERNANCE OUR COMMUNITIES OUR PEOPLE 2021 CORPORATE RESPONSIBILITY REPORT 10 O OU U R R C C OM OMP PA A NY NY BUILDING RESPONSIBLE, TRANSPARENT SUPPLY CHAINS Recent years have continued to underscore the importance of responsible supply chain management. Our suppliers are key partners in our business and we actively engage with them to establish clear expectations and understand where we can better collaborate to improve the environmental and social impact of our supply chain. We are committed to developing a supplier base that reflects our core values, demonstrates strong ethical business, and represents the diverse customers and communities we serve. Find out more about how T-Mobile manages a responsible supply chain and supports diverse s uppliers . ii PwC, 2020. The global economic impact of 5G .

5G Innovation Change Agent and Innovation Catalyst We are just beginning to see the possibilities unleashed by 5G. Speed, reliability, and greater capacity are driving innovation that can help meet the evolving needs of our customers and the planet― and make our lives run more efficiently. T-Mobile is at the center of this transformation, leveraging the power of our 5G network to fuel change across education, farming, healthcare, retail, transportation, and more. TAKING WAR MEMORIALS TO HEROES WHO CAN’T BE THERE 2021 CORPORATE RESPONSIBILITY REPORT Many veterans may not have the opportunity of seeing Washington, D.C.’s famed military memorials in person. But with 5G-enabled virtual reality (VR), our veterans can do that without ever leaving their home. In partnership with mixed reality company Healium and Honor Flight Network, T-Mobile created a VR experience that virtually transports veterans to Washington D.C.—just as if they were there in person. In the virtual tours, veterans can hear the sound of the Rainbow Pool, watch the Changing of the Guard at Arlington National Cemetery, and visit the World War II Memorial, Korean War Veterans Memorial, Vietnam Veterans Memorial, and the Women in Military Service for America Memorial. It’s a great example of 5G’s ability to enable VR applications that transport us to new places and better connect people to their worlds. For more information read the full story . BRINGING ANATOMY ALIVE FOR PRE-MED STUDENTS OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE NUMBERS AND SMALL PRINT 11 THE ENVIRONMENT OUR COMPANY Fisk University, located in Nashville, TN, is one of the top-ranked historically Black universities in the country. In 2021, they teamed up with T-Mobile, HTC VIVE, and VictoryXR to launch a first-of-its-kind interactive 5G-powered VR human cadaver lab for students in pre-med and biology- related majors. The virtual lab combines the in-person classroom experience with 5G-powered VR technology, enabling students to explore the complete skeletal structure, muscle structure, and the 11 human organ systems while engaging in-person with their classmates and instructors. This is just a taste of the learning experiences 5G is bringing to educational institutions everywhere. For more information read the full story .

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5G Innovation Continued HELPING YOUNG LEADERS SEE DIFFERENT FUTURES Many young people leave school without a clear picture of their career path or future ambitions. What if we could help them envision their future with the aid of 5G-powered VR? Using two mobile trailers equipped with T-Mobile 5G, the Oculus Quest, and HTC VIVE Pro 2 headsets, Future Leaders Outreach Network travels to schools and other community locations. There, they conduct a VR program that encourages young students to explore potential future occupations via 25 different career path simulations developed by VictoryXR, CareerLabsVR, and others. The career path simulations include industrial robot technicians, first responders, electricians, and more—all of which empower young people with a clearer picture of careers they can pursue to become future leaders and entrepreneurs. For more information read the full story . GROWING APPLES WITH 50% LESS WATER 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE NUMBERS AND SMALL PRINT 12 THE ENVIRONMENT OUR COMPANY Swan’s Trail Orchard not only grows some of the tastiest apples in Washington state, it has also become a smart farming pioneer in collaboration with T-Mobile, 5G Open Innovation Lab (an industry partnership set up to inspire innovation), and Innov8.ag (an agricultural technology start-up). With new 5G-enabled sensors that measure soil levels to a depth of 24 inches, apple trees can communicate water needs to farmers, enabling a more precise and sustainable approach to water management. Through this technology, Swan’s Trail discovered it had been running its irrigation system too frequently and could get the same or better results with 50% less water. Imagine the power of such a system in areas suffering from water shortages where large farms require millions of gallons to irrigate their crops. For more information read the full story . We’re Supercharging 5G Innovation T-Mobile created an ecosystem to meet innovators where they are—anywhere from ideation to incubation, prototyping and beyond. As a co-founder of the 5G Open Innovation Lab , we’ve helped establish a global applied innovation ecosystem of developers, corporate enterprises, academia, and government institutions, working together with early- and mid-stage ventures to fuel the development of transformative new capabilities. Through the T-Mobile Accelerator , an immersive technology program, we’re supporting start-ups and spurring the development of new, transformative applications. Early in 2022, we also launched the Tech Experience 5G Hub in Bellevue, WA that provides a 24,000 square foot collaborative workspace and lab for innovators to develop new products and services for our 5G network. And with the T-Mobile Ventures investment fund, we help fuel early and emerging growth companies in the development of groundbreaking 5G products and services for our network. With our leading 5G network as the foundation, we’re continuing to expand our 5G facilities and programs to drive further innovation.

THE ENVIRONMENT THE NUMBERS AND SMALL PRINT OUR GOVERNANCE OUR COMMUNITIES OUR PEOPLE 2021 CORPORATE RESPONSIBILITY REPORT 13 OUR COMPANY OUR GOVERNANCE RESPONSIBLE BUSINESS

Our Governance Winning is important, but how we get there matters just as much. Our success relies on the trust of our customers, suppliers, business partners, and one another. We don’t take this trust for granted; we seek to earn it every day—through uncompromising ethical conduct, socially and environmentally responsible business practices, and good governance. 2021 Highlights Created a Cyber Transformation Office reporting to the CEO THE ENVIRONMENT THE NUMBERS AND SMALL PRINT OUR COMMUNITIES OUR PEOPLE 2021 CORPORATE RESPONSIBILITY REPORT 14 OUR COMPANY OUR GOVERNANCE $ spen 3 t wit . h 2 di 7B verse suppliers 2 sca 1B m cal ls identified or blocked by T-Mobile Scam Shield™ 50% Board Diversity Half of our Board of Directors self-identify as women and/or members of traditionally underrepresented racial/ethnic groups Achieved target of 98%+ enterprise completion rate for T-Mobile’s Integrity365 Code of Business Conduct training 100% placement rate for 2021 NextTech Diversity Program graduates into full-time employment Lead Independent Board Director Independent Chair of the Audit, Compensation, and Nominating and Corporate Governance Committees 38% of suppliers * completed environmental and social assessments through EcoVadis * Based on sourceable spend

Ethical Business Practices Delivering Through High Ethical Standards There’s no room for compromise when it comes to doing business the right way. We conduct our business with high ethical standards to deliver the results our customers, stakeholders, and employees expect and deserve. Our Code of Business Conduct provides clear expectations on how we do it the right way at T-Mobile. It outlines the workplace conduct standards and legal guidelines we follow as part of our commitment to ethical business practices. We’re fair and honest in our business dealings. We don’t try to gain an unfair advantage over competitors, suppliers, or customers by deceiving anyone, taking advantage of confidential information, or fudging the facts. This includes compliance with U.S. and foreign laws barring corruption and bribery, conducting ourselves fairly and honestly in all business dealings, and abiding by antitrust rules and regulations. Our Code emphasizes fair competition. We do not conspire with our competitors to rig prices, fix bids, divvy up sales territories, or boycott particular suppliers or customers. Required Training We take a continuous learning approach so that T-Mobile’s Code of Business Conduct is integrated into our everyday business. Training takes place multiple times throughout the year and is required of all employees and officers of the company. This training covers topics such as Data Safety a nd Privacy, Anti-Corruption, Health and Safety, Harassment and Discrimination, and our Non-Retaliation policy, and enables everyone to understand our Code standards and commitment to ethical business practices. Additional ethical conduct policies are included in our company governance documents . All employees and officers of the company are required to complete T-Mobile’s Code of Business Conduct training each year. We regularly survey employees to help identify opportunities to strengthen our ethics culture and also have a centralized process for disclosing and addressing potential conflicts of interest. Governance and Oversight The Chief Compliance Officer provides an annual report to the Nominating and Corporate Governance Committee on the effectiveness of our compliance and ethics programs, using data analysis, key performance indicators, and external benchmarks to measure performance. To underscore our ongoing commitment to developing, evolving, and refining our business practices, we periodically conduct anti-corruption compliance risk assessments. Through these assessments, we identify key opportunities to further strengthen our training program and other aspects of our compliance and ethics programs. DOING RIGHT FOR OUR CUSTOMERS 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR COMMUNITIES THE NUMBERS AND SMALL PRINT 15 OUR COMPANY THE ENVIRONMENT For almost a decade, our Un-carrier revolution has been about doing the right thing for our customers. It began with ending annual service contracts, data limits and overages, and international data charges, while providing more value for the money, revolutionizing customer care, and bringing a sense of humanity and fun to the wireless industry. Today, we keep giving more of what customers love without asking for more—from Price Lock, Internet Freedom, and Coverage Beyond to free mobile entertainment and free scam-blocking protection— all to help customers save money while enjoying a superior experience in both wireless and high-speed internet service. We treat customers honestly and fairly. That means giving customers complete and transparent information about our products and services. It means delivering what we promise. And it means we don’t charge customers for things they haven’t authorized. Additionally, T-Mobile abides by the practices outlined in the Consumer Code for Wireless Service from CTIA, the trade association representing the wireless industry. By marketing and selling responsibly, we help our customers avoid bill shock and confusing account balance information. How We Operate, According to Our Code of Business Conduct We Do It the Right Way. Always. We Take Care of Our Customers We Respect Each Other and Our Environment We Demonstrate Integrity 24/7 We Do Business Right We Protect T-Mobile Information and Assets OUR GOVERNANCE

Feature Story: Ethical Business Practices BRINGING OUR CODE TO LIFE “Do It the Right Way. Always.” This is one of our core values and foundational to our Code of Business Conduct. That’s why we work so hard to enable all our employees to understand what the Code means and how it translates to their jobs. Integrity365 (i365) is our innovative professional standards training curriculum that brings our Code to life for all employees. Featuring members of Team Magenta, including executives, the TV show format delivers T-Mobile’s annual required compliance and ethics training through refreshers and practical, interactive examples of what it means to do the right thing every single day across a variety of situations. A typical i365 episode includes video-based stories addressing different Code topics through realistic, at-work situations that help employees identify concerns through multiple choice responses to the ethical conduct questions. This training is especially effective because it allows employees to participate in making the right decisions based on the values and principles of the Code. We also created a Manager Edition specifically for people managers which provides supplemental training to equip them to engage their teams on the core principles of T-Mobile’s Code. People managers can access an i365 dashboard to track and drive their team’s training completion. As part of the onboarding process, we also provide our new hires with a tailored edition of i365 to empower them to start off doing it the right way—always. They are required to complete the training during their first four weeks on the job. All employees are required to complete each episode of i365 or other Code training, and quarterly completion reports for all lines of business are submitted to the N ominating and Corporate Governance Committee. This engaging and thorough approach to training helps embed our commitment to ethical business standards into our culture and stay in compliance with federal and state laws and regulations, as well as our own policies. VIDEO TRAINING ON EVERY ETHICS TOPIC i365 training occurs throughout the year and covers the core topics of our Code of Business Conduct, including the following: ■ We Respect Each Other —Standards of professional conduct for T-Mobile employees when interacting with each other ■ Addressing Harassment & Discrimination — How to recognize discrimination and harassment in the workplace and what to do if you are a victim or an observer ■ Protecting Information the Right Way — Importance of and best practices for protecting T-Mobile assets and information, including customers’ personal data ■ Demonstrate Integrity —How to comply with equities trading regulations, conflicts of interest, and giving and receiving gifts ■ Doing Business Right —Awareness of anti- corruption and antitrust rules, government ethics rules and ethical marketing practices ■ Social Media the Right Way —The dos and don’ts of using social media while employed by T-Mobile ■ Speaking Up at T-Mobile —Why speaking up is important, when to speak up, and how to speak up At the end of each course, employees are asked to give feedback on the training. Our Compliance team regularly tracks this feedback, along with completion and engagement rates, to assess overall satisfaction with the training, relevance to everyday job duties, and impact on behavior. This enables T-Mobile to continuously incorporate feedback and learnings into new iterations of i365. THE ENVIRONMENT THE NUMBERS AND SMALL PRINT OUR COMMUNITIES OUR PEOPLE 2021 CORPORATE RESPONSIBILITY REPORT 16 OUR COMPANY OUR GOVERNANCE IN CONVERSATION WITH DAVID WERBLOW, T-MOBILE’S CHIEF COMPLIANCE OFFICER David talks about keeping ethical business conduct at the forefront for employees and evolving the program to address ongoing feedback. Our compliance and ethics programs aspire first and foremost to empower employees to do it the right way through clear policies and effective training. Even with effective training, we understand that the best way to handle an ethical issue in a particular situation is not always clear so we invite and encourage employees to reach out when they have a question about how they should respond the right way. We have an Integrity Line and work diligently to ensure our employees know it exists, know how to access it, and feel confident that their concerns can be reported anonymously, if that’s their preference. Our Speak Up Policy protects employees who raise good faith concerns from retaliation. We also continuously evaluate our performance to help us ensure our programs are effective. We really dive into the data. We conduct surveys and scrutinize the results to make sure we have an accurate assessment of how we are executing on compliance. Through careful analysis of reported concerns and outcomes, we identify trends in a timely manner and then are thoughtful, strategic, and holistic about next steps. While I’m happy to say we get great and candid feedback from employees, we are never satisfied with the status quo and are always striving for continuous improvement. To tap into another core T-Mobile value: We Won’t Stop!”

Ethical Business Practices Continued Encouraging Employees to Speak Up In our Code of Business Conduct, and through our Speak Up Policy , we encourage anyone to report a concern, a possible violation of our policies, or to seek advice on how to implement the organization’s policies and practices for responsible business conduct. We provide employees with means to speak up anonymously and without fear of retaliation through our third-party Integrity Line (online or by phone), by emailing our Compliance & Ethics team, or contacting our Chief Compliance Officer or the Chair of the Audit Committee directly. Our Speak Up Policy outlines how people are protected from retaliation whenever they raise or report suspected misconduct or a potential violation of the law in good faith. Our Commitment to Human Rights T-Mobile is deeply committed to human rights. We believe we have a responsibility to manage our business in a manner consistent with this commitment, and we expect the same of our affiliates, business partners, and their stakeholders. Our Human Rights Statement covers such areas as discrimination, working conditions, and freedom of expression. It is informed by a number of international instruments, including the United Nations Guiding Principles on Business and Human Rights, the United Nations Universal Declaration of Human Rights, and the International Labour Organization’s 1998 Declaration on Fundamental Principles and Rights at Work. Consistent with our commitment to open dialogue and engagement, we consult with relevant stakeholders to understand human rights-related concerns, issues, and opportunities in order to assess and escalate them as appropriate. The leaders of our Human Resources, Corporate Social Responsibility, and Legal Affairs teams are responsible for overseeing the commitments outlined in our Human Rights Statement. Political Engagement Public policy shapes our business landscape every day. Engaging in the political process is an important part of how T-Mobile advocates for our business and our customers. We do so transparently and responsibly through corporate political contributions, contributions from an employee-funded political action committee (PAC), lobbying, and contributions to tax-exempt organizations. Through these efforts we work to support candidates who share T-Mobile’s views on important issues directly related to our business. We annually publish a Political Engagement Report , which chronicles our contributions and lists our trade association memberships. Through these activities, we leverage our powerful brand and scale to deliver more for our shareholders, consumers, and employees. A few bedrock commitments guide our political activities: strict compliance with local, state, and federal laws; bipartisan contributions; and strict adherence to our Code of Business Conduct and our Political Activities and Lobbying policy. Our General Counsel provides an annual report to the Nominating and Corporate Governance Committee on our political contributions and engagement. 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR COMMUNITIES THE NUMBERS AND SMALL PRINT 17 OUR COMPANY THE ENVIRONMENT OUR GOVERNANCE

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Corporate Governance Fostering Good Corporate Governance Doing it the right way and building public trust in our company takes good leadership. Two important bodies of T-Mobile’s governance and management structure are our Board of Directors and our Senior Leadership Team. Our Board of Directors is made up of dynamic and experienced leaders from across industries who provide counsel and direction to promote our long-term success. The full Board has overall responsibility for risk oversight and is supported by key committees with delegated risk oversight responsibility for certain topics. We provide orientation to our directors to give them f amiliarity with the company’s business, industry, and corporate governance practices and policies. Additionally, we make available to the directors continuing education programs that enable them to update and gain new skills in areas including important ESG topics, such as cybersecurity, and the evolving regulatory landscape. Our Board of Directors has adopted our Code of Business C onduct as well as our Code of Ethics for Senior Financial Officers, which is applicable to our CEO, Chief Financial Officer, Chief Accounting Officer, Treasurer, and Controller. Board Independence and ESG Oversight Since Deutsche Telekom controls more than a majority of t he outstanding shares of our common stock, we are deemed a “controlled company” under the NASDAQ Stock Market LLC rules. These rules exempt “controlled companies,” like us, from certain corporate governance requirements, including certain Board and committee independence requirements. Nevertheless, each of the Audit Committee, the C ompensation Committee, and the Nominating and Corporate Governance Committee of the Board is chaired by independent directors, with the Audit Committee consisting of all independent directors. The Compensation Committee has also retained Mercer (a wholly owned subsidiary of Marsh & McLennan Companies, Inc.), a well-recognized employee benefits and compensation consulting firm, as its independent compensation consultant. In addition, our Board has chosen to appoint a lead independent director. To promote oversight of critical ESG issues, risks, c ompliance, and progress on initiatives, T-Mobile executives report updates to the Audit Committee and Nominating and Corporate Governance Committee. BOARD DIVERSIT * 50% identify as women and/or members of traditionally underrepresented racial/ethnic groups 28.6% identify as women 28.6% identify as members of a traditionally underrepresented racial/ethnic group The Audit Committee receives quarterly enterprise-wide risk assessment reporting, which includes risks relating to cybersecurity and privacy, business continuity, annual fraud risk assessment, and SOX and Internal Audit reporting or assessments from management and our internal audit lead. The Audit Committee is also apprised of any significant issues identified as a result of our Enterprise Risk and Compliance assessments. The Nominating and Corporate Governance Committee r eceives quarterly briefings on progress, updates, and initiatives related to key ESG topics such as cybersecurity and data privacy, political contributions, philanthropic giving, and environmental sustainability. See our Governance Documents for more information. Board Diversity We understand diversity, inclusive of gender, race, and e xperience, is a critical attribute of a well-functioning Board of Directors and a measure of sound corporate governance. Our director selection guidelines define diversity broadly to include factors such as gender and race, as well as age, ethnicity, geographic, cultural, and professional diversity. The composition of the Board has continued to evolve. A s of December 31, 2021, 50% (7 out of 14) of our Board of Directors identify as women and/or members of traditionally underrepresented racial/ethnic groups. In addition to our Board of Directors, we have an e xperienced Senior Leadership Team. As of December 31, 2021, our leadership consisted of 17 executives with 41% identifying as women or members of traditionally underrepresented racial/ethnic groups. Learn more about our executives and directors . Y *All data points relating to the T-Mobile Board of Directors are as of December 31, 2021. T-Mobile Board Governance Highlights Separation of Chairman and Chief Executive Officer Roles Stockholder Right to Call Special Meeting a nd Act by Written Consent Lead Independent Director Independent Chairs of the Audit, C ompensation, and Nominating and Corporate Governance Committees Executive Compensation Driven by P ay for Performance 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR C OMMUNITIES THE NUMBERS A ND SMALL PRINT 18 OUR COMPANY THE ENVIRONMENT OUR GOVERNANCE

Business Continuity Being Prepared and Building Resiliency Business disruptions come in all shapes and sizes—from natural disasters and pandemics to staffing issues and equipment or application failures. When a disruption does occur, preparedness planning can make all the difference. Our Enterprise Continuity Program considers the full range of natural and man-made events that could impact our customers, employees, operations, and assets across the country and develops risk mitigation and business continuity strategies to keep our teams prepared and our customers connected. Planning with an “All Hazards” Mindset At T-Mobile, we develop business continuity and emergency preparedness plans with an “all hazards” mindset, meaning we have plans in place for a wide range of business disruptions and proactively find ways to eliminate any single points of failure. Our enterprise continuity team works with every team in the company to conduct annual reviews and update our Business Continuity Plans, ensuring they are current, comprehensive, and effective so the company is ready to coordinate and respond to any new event. The enterprise continuity team utilizes tools such as a Business Impact Analysis to examine each part of our business and network to determine the impact and severity of different disruptions on our customers, employees, and infrastructure. This helps us prioritize recovery tasks and identify interdependencies, ensuring that our contingency plans are resilient and all-encompassing. We know how much our customers rely on their connectivity and we invest heavily in the resiliency of our network through network design and operational redundancies that significantly reduce the chance of network failure. As a result of a multi-year network hardening investment we added thousands of backup generators and advanced relief and recovery tools to better equip network switches, data centers, and other critical sites in hurricane-prone areas. Climate Risk and Oversight As the frequency and severity of extreme weather events increase, evaluating climate-related risks and preparing for natural disasters and regional power outages has become increasingly critical to our business. T-Mobile’s President of Technology oversees the company’s network resilience strategy, which includes evaluating technology disruptions and climate-related impacts to develop and continually update risk mitigation plans. Our Enterprise Risk Management team also partners with groups across the company to track progress on network resiliency, such as the effectiveness of power backup systems in data centers and the network hardening efforts in at-risk areas. As part of the risk assessment process, our network sites are evaluated for vulnerabilities to environmental change. To help ensure business-critical risks are overseen and communicated at the Board level, the Senior Vice President of Internal Audit & Risk Management serves as the Chief Audit Executive and has a direct communication channel to the Audit Committee for purposes of reporting or discussing concerns. The Chief Audit Executive receives quarterly status reports on the Enterprise Continuity Program and provides a quarterly enterprise-wide risk assessment report to the Audit Committee. Each year we evaluate our Enterprise Continuity Program and review our risk management procedures and evolve them as needed to help mitigate against evolving threats. Ready to Respond When an emergency does occur, we quickly implement our preparedness plans to keep our employees safe and customers connected. Our Enterprise Incident Management team manages a virtual Emergency Operations Center to oversee and coordinate the company’s response throughout the event. This enables us to work effectively with stakeholders inside and outside of our business, from emergency engineering and community support teams on the ground, to retail staff, local authorities, meteorologists, and political leaders. It’s this approach that enables us to move quickly. Beyond working to maintain connectivity and services, we’re also proud of the humanitarian assistance we provide to affected communities through our disaster relief efforts. For more information, see the Natural Disaster and Community Support section. 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR COMMUNITIES THE NUMBERS AND SMALL PRINT 19 OUR COMPANY THE ENVIRONMENT OUR GOVERNANCE

Data Privacy Keeping Our Customer Data Safe and Secure We love our customers. Earning and keeping their trust by respecting and protecting their data is central to how we operate. This is vital to our business, and it’s the right thing to do for our customers. Early in 2021, we launched an updated Privacy Center to give customers a clear and simple explanation of how their data is used and how they can manage it. There, customers can find the T-Mobile Privacy Notice, Children’s Privacy Notice, and other important privacy information, including educational content for consumers on how to better protect themselves and their data. This is how we help cut through the complexity of data privacy and security for our customers and make it easy to learn about the information we collect, how we use it, and the measures in place to protect it. Our Pillars of Privacy At T-Mobile, data privacy is built around five principles: trust, transparency, control, education, and protection. Together these principles drive what privacy looks like across our company. Tr u s t We value the privacy of the data that is entrusted to us. We believe that every customer deserves core privacy protection practices and to only have their data used for legitimate business purposes. That includes not using it to send unwanted marketing communications and preventing harmful biases in our algorithms. Transparency We’re open and honest about our privacy practices and the way we process personal data. We inform customers of important updates to our Privacy Notice and how they can exercise privacy choices and set preferences by using simple, clear language and easy-to-find information. Our annual Transparency Report provides additional information and data on how we deal with law enforcement and national security requests for customer data. Control We put our customers in control when it comes to their data and their preferences. With simple, clear data choices, customers can easily access and delete their data and set marketing preferences. We offer all U.S. customers choices to opt out of targeted advertising, even in states where it’s not legally required. Our Customer Care teams are equipped to assist customers with questions about the data controls available. Education We help customers understand privacy and data use so they can make the right choices. One way we do this is by providing educational resources and video guides for customers on a range of topics across data transparency, data-sharing, and marketing choices, and security and controls for the whole family. Protection T-Mobile works to protect the customer data we collect. For products that use personal data, it’s our policy to collect only what’s necessary, retain it as outlined in our retention policy, and delete it after use. We work with our suppliers and partners so that they are also applying reasonable safeguards. T-Mobile was the first U.S. wireless provider to implement number verification in 2019. We also led the industry in 2020 in implementing STIR/ SHAKEN with all major U.S. network providers to fight number spoofing and further protect customers from scammers and unwanted robocalls. Scam Shield™ adds further protections from spammers and scammers. For more details, see the Cybersecurity section. 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR COMMUNITIES THE NUMBERS AND SMALL PRINT 20 OUR COMPANY THE ENVIRONMENT OUR GOVERNANCE

Empowering Employees to be Data Privacy Champions We want everyone at T-Mobile to be a data privacy champion. We provide annual data privacy training through i365 and year-round awareness programs so that employees know how to keep customer data confidential in different scenarios, with additional training for roles that involve handling personal information. All employees are required to uphold the privacy and security obligations outlined in our internal corporate policies, including our Code of Business Conduct, Information Security Policy, Records Management Policy, Information Handling Policy, Information Handling Procedure, Information Classification Standard, and Acceptable Use Policy. We work to further weave a culture of privacy and security throughout the business by engaging our Security and Privacy Ambassador Network (SPAN), which acts as an extension of our Privacy Office. Members of SPAN are embedded across the company and equipped with enhanced privacy knowledge to raise awareness, oversee adoption of privacy and security practices, and proactively elevate important matters to the Privacy Office. SAFER CHOICES FOR FAMILIES Digital connectivity allows us to keep connected to loved ones, but it also opens up a world that can be tricky to navigate, especially for families with children. Parenting in the digital age isn’t always easy, but T-Mobile is giving parents and guardians better options for managing their children’s online activities and screen time so they can feel confident about the way their family interacts with digital technology. With T-Mobile, parents and guardians can choose what’s right for their family through both free and paid services. Our free Web Guard service lets customers apply different filter levels to restrict adult content from being seen or accessed by family members. FamilyMode® can be selected for a cost for those who want to keep track of their family members’ locations in real time, set content filters, and monitor screen time to help develop good digital habits. Parents can even use the FamilyMode® app to give extra screen time as a reward or to pause the internet when a break is called for. We’re always looking for new ways to safeguard children and protect their privacy through the products and services we offer. We piloted our Kid’s Line in 2021 for our postpaid customers, with plans to expand access to all of our customers. This feature enables parents and guardians to designate any line on their account as a Kid’s Line if it’s being used by a child under the age of 16. Once designated a Kid’s Line, we won’t use that line’s data for advertising, and we’ll opt the line out of our marketing communications. To learn more, check out our Children’s Privacy Notice . Our Privacy Office routinely evaluates our corporate policies, procedures, and training programs to provide employees with evolving data privacy and security requirements and ensure they have the resources they need to protect customer privacy. Data Privacy Oversight and Controls T-Mobile has an established governance and controls p rocess in place to help ensure that our data privacy policies and practices are effectively implemented. The highest level of oversight comes from our Nominating and Corporate Governance Committee of the Board of Directors. In addition to Board level oversight, T-Mobile’s data p rivacy team and cybersecurity team jointly report to the Information Security and Privacy Council, which includes members of the Senior Leadership Team. Together, these groups monitor the effectiveness of T-Mobile’s data privacy programs. Safety through Innovation: T-Mobile’s SyncUP KIDS Watch helps parents protect their children by enabling a safe entry into the digital world. Parents are able to track their kid’s location in real time and get alerts when they enter or exit a virtual boundary. The watch also allows the child to alert their contacts if they need help or hit a button to call 911 in an emergency. GIVING CUSTOMERS CONTROL OF HOW THEIR DATA IS USED We use some information, like adult age range and apps installed on a customer’s device, for advertising purposes. This information is attributed to Advertising IDs, which are pooled to create audience segments based on customer interests, like sports or entertainment. When we share data, we only share the audience segment name, like “business traveler.” We do not share underlying customer broadband or device usage data with third parties for advertising purposes. And we never share information for advertising purposes that directly identifies customers, such as name, address, email, or precise location information. This enables the delivery of offers and ads for pr oducts and services based on customer interests. As always, our goal is to deliver the best experience to our customers. Through their My T-Mobile account, customers can opt out or change their advertising preferences at any time. For more information about customers’ choices, please visit our Privacy Notice . Data Privacy Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR COMMUNITIES THE NUMBERS AND SMALL PRINT 21 OUR COMPANY THE ENVIRONMENT OUR GOVERNANCE

Cybersecurity Focusing on Cybersecurity Our customers depend on us to keep them connected. With bad actors around the world constantly attacking the security of corporate systems, we continue to accelerate our focus on protecting our customers and enhancing our cybersecurity measures. Keeping our network and systems secure and earning the trust of our customers is paramount to us. Transforming Our Cybersecurity Approach In 2021, we established the Cyber Transformation Office led by a Chief Cyber Transformation Officer. Reporting directly to the CEO, this department is focused on embedding cybersecurity competencies and a security- first mindset across our culture. Our Cybersecurity Trust and Protection organization has also been integrated into this new office to foster greater collaboration across the teams and the business. These leaders work collaboratively with other senior leaders on the Information Security and Privacy Council, with the mission to define, organize, and continuously communicate the strategic direction of cybersecurity and privacy for the company. The Cyber Transformation Office spearheads our holistic approach to cybersecurity management and includes state-of-the-art cybersecurity technology, stringent security protocols, rigorous monitoring and response operations, and compliance consistent with global industry standards. We combine strong oversight and governance controls with technical and physical safeguards, while incorporating core functions from the widely recognized National Institute of Standards and Technology (NIST) Cybersecurity Framework. Our Chief Cyber Transformation Officer and Chief S ecurity Officer provide reports four times a year to the Nominating and Corporate Governance Committee on T-Mobile’s data information and infrastructure security programs. Security-First Mindset Our holistic approach involves every employee— because we all have a part to play in keeping T-Mobile secure. We train employees throughout the year via i365 and other targeted cybersecurity trainings, which enlist everyone to help identify and remediate potential threats and provide engaging scenario-based training covering phishing attacks, good password hygiene, proper handling of customers’ privacy choices, and other topics. We’re committed to addressing every aspect of data security. While we have processes to identify and protect our systems, detect and respond to threats, and recover if attacks are successful, security incidents can still occur. We invest in internal expertise and work with top security experts from around the globe, leveraging their expertise to strengthen our capabilities and further protect T-Mobile and our customers. We have invested in strategic partnerships with Accenture, KPMG, and Mandiant—industry leaders in cybersecurity technology and services. Countering All Forms of Fraud Fraud continues to be an industry-wide problem that we are constantly working to deter. We offer customers a variety of safeguards against these criminal attacks to help them protect their personal information. Our award-winning support teams work with customers directly to address concerns about potential fraud or to discuss security measures available to them. We maintain security incident response plans to investigate and remediate incidents involving unauthorized access to personal data, and we are continually maturing our safeguards to respond to new risks. We recognize we’ll always have work to do in this ever-evolving space. 2021 CORPORATE RESPONSIBILITY REPORT SCAM SHIELD™ In 2020, T-Mobile launched Scam Shield™, making the Un-carrier the first major wireless provider to help protect every customer against robocallers, scammers, and fraudsters. No special device, app, or plan is required. Unlike a third-party app or other passive monitoring solutions, Scam Shield™ is built into our network, leveraging the power of T-Mobile’s entire network to keep our customers protected. Using AI, machine learning, and patented technologies, we analyze call behavior to protect customers around the clock, responding to new threats and updating protections every six minutes. In 2021, we added new features including improved Scam Reporting and eSIM support, as well as new patented network tools to further identify and block likely scam attempts. The spammers and scammers keep trying, but we’ve got their number: by December 2021, Scam Shield™ identified or blocked over 21 billion scam calls. That’s 700 calls intercepted per second. 21 billion scam calls identified or blocked OUR PEOPLE OUR COMMUNITIES THE NUMBERS AND SMALL PRINT 22 OUR COMPANY THE ENVIRONMENT OUR GOVERNANCE

Responsible Supply Chain Optimizing Supply Chains for People and the Planet The success of our business depends on the strong relationships we build with our wide and diverse network of global suppliers. We develop long-lasting, trusting, and mutually beneficial relationships with suppliers that share our strong values and operate in a responsible and sustainable way. T-Mobile suppliers are expected to share our commitment to doing things the right way while conducting business either with or on behalf of T-Mobile. Governing Our Supply Chain in the Right Way Our Supplier Code of Conduct governs our supply chain and sets out expectations for supplier conduct in areas ranging from customer care and integrity to reducing greenhouse gas (GHG) emissions and water use, responsibly sourcing materials, and protecting human rights. We expect suppliers to promptly report concerns about violations of the Code to the T-Mobile Integrity Line . We also provide detailed Responsible Sourcing Guidelines which recognize the human rights and environmental risks associated with extracting, transporting, and trading certain natural resources such as conflict minerals and paper fiber. For more information, see the Natural Resources Management section. Our Human Rights Statement and Environmental Policy also apply to our suppliers. While our suppliers have the responsibility to undertake their own work to address human rights and environmental issues, we are committed to supporting their efforts. Monitoring Risks with Third-Party Risk Management Even before suppliers are selected, a centralized Third-Party Risk Management (TPRM) process screens for anti-corruption, global sanctions and human rights violations, and financial, security, reputational, and environmental risks. Supplier risk assessments are performed on an ongoing basis depending on the risk profile of the supplier, with the goal of ensuring we are not conducting business with any supplier that could pose a risk to our operations or reputation. Our TPRM process also continually monitors current suppliers for policy violations and risks through automated, real-time workflows that look for any adverse news or changes in supplier risk profiles. Additionally, Supplier Code of Conduct compliance is affirmed through standard supplier contract terms, TPRM assessment questionnaires, and Procurement’s vendor onboarding forms. Events or issues detected by TPRM monitoring are escalated to the enterprise Legal, Compliance, and business teams for review and recommended handling. Science-Based Targets for Suppliers Setting science-based emissions reduction targets has helped us dramatically reduce our GHG emissions. That’s why we encourage our suppliers to set their own science-based reduction targets by working with the Science Based Targets initiative (SBTi), and to bring them in line with the world’s ambition to limit global warming to 1.5°C. The more companies we can influence toward setting and achieving science-based targets, the bigger emissions reductions we can achieve together, and the better off our planet will be. INCREASED VISIBILITY INTO SUPPLY CHAIN SUSTAINABILITY EcoVadis is a leading provider of business sustainability ratings, helping businesses to better evaluate the environmental, social, and ethical performance of their own operations and those in their supply chain. In 2020, we  began using their supplier assessment to better evaluate our supply chain across four key areas: environment, labor and human rights, ethics, and sustainable procurement. Each supplier who participates is evaluated with a rigorous evidence- based scorecard that identifies strengths and areas of opportunity. This gives us a chance to better engage with our suppliers on key issues in the four categories and drive improvements that benefit us all. In 2021, we strengthened our practices around supplier scoring and officially integrated the EcoVadis evaluation into our TPRM process. Going forward, we are continuing to increase the number of suppliers assessed. 38% of sourceable spend assessed by EcoVadis in 2021 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR COMMUNITIES THE NUMBERS AND SMALL PRINT 23 OUR COMPANY THE ENVIRONMENT OUR GOVERNANCE

Building a Diverse Supply Chain We’re continuing to strengthen the diversity of our suppliers to ensure a more representative, resilient, and economically inclusive supply chain that spurs positive change in industries beyond our own. To drive diversity in our supply chain, we’re educating employees on how to promote our supplier diversity efforts and are rewarding their progress. We’re also taking steps to directly invest in initiatives that train underrepresented groups for jobs critical to our supply chain. Identifying Opportunities for Progress In 2021, we implemented our Supplier Diversity Category Management Strategy for our network technology procurement organization, covering all T-Mobile’s spend outside of wireless devices. This strategy enables category managers to identify the supplier diversity spend more easily in the areas they oversee, which helps them to identify opportunities and develop actionable targets that lead to progress. We also implemented a reward and recognition program to recognize Procurement Sourcing Managers who actively work with traditionally underrepresented, disadvantaged, and/or small business owners and award new contracts to these businesses. Driving Inclusive and Equitable Programs To invest in a more diverse supply chain, we launched the NextTech Diversity Program to provide career training and job placement for hundreds of candidates from traditionally underrepresented backgrounds, helping them take on meaningful employment within the telecommunications industry. We also co-launched Diversity in Clean Energy (DiCE) in 2021, to drive inclusive and equitable practices in sourcing and supplier selection across the clean energy value chain. Programs like these are having an impact. In 2021, we spent $3.27 billion with suppliers from traditionally underrepresented backgrounds, putting us on track to achieve our goal of joining the Billion Dollar Roundtable for supply chain diversity excellence by 2025. The Billion Dollar Roundtable was created in 2001 to recognize corporations that annually spend at least $1 billion with minority and women-owned suppliers. $3.27 billion spent with suppliers from traditionally underrepresented backgrounds Responsible Supply Chain Continued Recognition for Supporting Supplier Diversity in 2021 Recognized by Military Friendly® for supplier diversity Best of the Best top 50 corporations for inclusion— National Business Inclusion Consortium Corporation of the Year Asian Business Association of Los Angeles (ABALA) Diversity & Inclusion of the Year Award Greater Los Angeles African American Chamber of Commerce (GLAAACC) Industry Change Agent of the Year Learning Alliance Corporation 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR COMMUNITIES THE NUMBERS AND SMALL PRINT 24 OUR COMPANY THE ENVIRONMENT OUR GOVERNANCE

Responsible Supply Chain Continued Training the NextTech Generation A team of inner-city youth are climbing a cellular mast for the first time in helmets and safety gear. This isn’t a real mast. It’s a training structure for future technicians. Once their training is done, many of them will be up in the sky for real and on a new career track as part of the skilled workforce making the 5G revolution possible. The training exercise is part of the NextTech Diversity Program, which is designed to connect women and men of color with the skills, training, and opportunities to become network technicians. For many, it’s a life-changing experience. Not a lot of people look like me in the industry,” says Mike Penn, who graduated from the program to become a certified 5G tower technician. “The NextTech industry is paving the way. I love my job and I can definitely see myself doing this for a long time.” 100% of the 2021 program graduates have been placed in full-time employment Equipping People of Color for Opportunities in 5G Transporting and building 5G infrastructure across all wireless providers will require an estimated 20,000 field technicians and trained tower crew workers . But people of color comprise a disproportionately small percentage of workers in the field. T-Mobile established the NextTech Diversity Program to change that—connecting an industry need for skilled workers with a group that’s underrepresented in this part of the workforce. iii As part of our Equity In Action efforts, the program began in January 2021 with seed funding to train and graduate everyone who participates. The program also guarantees job placements for those who graduate with a technician’s certificate or commercial driving license. A Successful Year One The program celebrated its first anniversary in February 2022, boasting a 100% graduation and career placement rate for the 70 participants in the inaugural network technician and equipment driver classes. “I am so proud to be managing an exciting T-Mobile program aimed at supporting women and men of color within underrepresented communities,” says Joyce Christanio, senior program manager of NextTech for T-Mobile. “I can personally identify with and whole- heartedly embrace this program because, as a youth, I too lived in an underrepresented community. Being privy to unfortunate situations occurring in inner-city communities, such as drug deals, neighbors with addictions, robberies, and losing a brother to senseless gun violence, I understand the importance of lending a hand to others to improve their lifestyles. While not everyone can’t afford a college education, this program provides individuals a hand to exceed a minimum wage salary, resulting in sustainable careers.” The NextTech Diversity Program started with an initial cohort to train future network technicians through the Learning Alliance Corporation, and added the Equipment Driver Program in the fall of 2021 through the New Reflections Technical Institute. Plans to expand don’t stop there. In 2022, T-Mobile doubled the NextTech Diversity’s Technician Program class from 50 students in 2021 to 100 students in 2022 and grew the Equipment Driver Program from 20 students to 50. iii T-Mobile.com, Investing in communities and people to build wireless networks . 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR COMMUNITIES THE NUMBERS AND SMALL PRINT 25 OUR COMPANY THE ENVIRONMENT OUR GOVERNANCE

OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE NUMBERS AND SMALL PRINT OUR COMPANY THE ENVIRONMENT 2021 CORPORATE RESPONSIBILITY REPORT 26 OUR PEOPLE EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES EQUITABLE OPPORTUNITIES E OUR PEOPL E Q U I TA B L E OPPORTUNITIES

Our People Our people are the heart and soul of the Un-carrier. We all win when we each bring our full selves to work each day. So, we embed DE&I in all we do, from hiring and employee development, to our award-winning culture and Equity In Action plan—to keep breaking down barriers and rewriting the rules. Together, we are unstoppable! 2021 Highlights 50% of Equity In Action Promises achieved Reached 69% of our goal to hire 10,000 veterans and military spouses by 2023 emp 60% loyees of color emp 41 loy % ees identify as women Released 2021 Federal EEO-1 Report ~$20.2M in tuition assistance invested in 5,500+ employees 1st in U.S. wireless industry to earn WELL Health-Safety certification 100% on the Human Rights Campaign’s Corporate Equality Index & Disability:IN’s Disability Equality Index All employees eligible for health benefits on day one of their employment iv Excluding interns iv 5 hou . rs o 4 f e M+ mployee training completed THE ENVIRONMENT THE NUMBERS AND SMALL PRINT OUR GOVERNANCE OUR COMMUNITIES 2021 CORPORATE RESPONSIBILITY REPORT 27 OUR COMPANY OUR PEOPLE

Our Culture Famous for Our Culture Our culture begins and ends with our employees. We are a celebratory, inclusive, magenta-loving team of people united in our commitment to change our industry for the better. Due to the pandemic and political and social unrest, the last two years have been difficult for people and companies everywhere. T-Mobile is no exception as we prioritized the health and safety of our employees while simultaneously integrating two companies into one unified culture. But if there is one constant that stayed true, it’s that Team Magenta is resilient, strong, proud, and unwavering in our commitment to our customers and to one another. And that’s why we have been so focused on getting it right. We are one team, together. The Future Is Magenta Our culture is something we never take for granted. It’s what unifies us in our mission to be the best in the world at connecting customers to their world, and what motivates us each and every day to be a part of something bigger. We work hard to stay connected to Team Magenta and have a variety of tools and forums to do that. One of the most important ways that we measure the health of our culture is through our confidential Our Voice surveys, which go out multiple times each year to all employees. The survey helps us to gauge how employees feel about our company, what they love about their jobs and what they don’t. It’s a big part of how we continue to evolve and grow. In October 2021, approximately 39,000 employees took the survey and relayed the following sentiment: ■ 87% of employees say their team clearly prioritizes the customer experience in its work ■ 86% of employees say their own team creates an inclusive work environment “for me to be myself” ■ 80% of employees would recommend T-Mobile as a great place to work AN AWARD-WINNING PLACE TO WORK T-Mobile has once again been recognized as a great place to work by leading national workplace awards and surveys. The following 2021 rankings are based on survey responses from the real experts: our employees. ■ America’s Best Employers list by Forbes ■ Comparably’s Best Global Culture list ■ Fortune 100 Best Companies to Work For ■ Glassdoor’s Best Places to Work list We attribute our success to our unique culture and values. They’ve ensured we’ve grown closer through challenging times and success alike—and they’ll guide us through an exciting new era of Un-carrier, too. Employee Forums In addition to Our Voice surveys and roundtable discussions with our directors and VP’s, our CEO and leadership team hosts quarterly All-Employee Meetings where they share the latest company news, celebrate wins, and discuss challenges ahead. These always feature an open Q&A session, the highest rated portion of the meeting, where everyone has a chance to engage on what’s top of mind. Past All-Employee Meetings have included a discussion of new service offerings, how the company is navigating the pandemic, and how—through our values—we can have a bigger, better, and more meaningful impact together. Building and maintaining a culture we can be famous for requires care and commitment. It’s something we take seriously and is work that’s constantly evolving. Our Culture is: Fun and celebratory We have a sense of humor and celebrate successes and one other Proud We love our T-Mobile branded gear. Like, a lot Inclusive We ALL belong Action-oriented We are relentless in our commitment to deliver results Customer-obsessed We fight on behalf of all customers 2021 CORPORATE RESPONSIBILITY REPORT OUR GOVERNANCE OUR COMMUNITIES THE NUMBERS AND SMALL PRINT 28 OUR COMPANY THE ENVIRONMENT OUR PEOPLE

Diversity, Equity, and Inclusion Committed to DE&I Our diverse workforce reflects the communities we serve and positions us to deliver incredible experiences for our customers. It’s not enough to say we support DE&I—we have a responsibility to put our words into action every day. Following our merger with Sprint, we deepened our commitment by launching our five-year Equity In Action (EIA) plan. This bold plan puts DE&I at the center of everything we do for our employees, our customers, and our communities. We built EIA by listening to our employees. Their feedback offered a wealth of insight that helped map out a plan to address where we needed to evolve, shift, and align as an organization. This led to three focus areas that anchor our EIA plan. The Three Pillars of Equity In Action TALENT We will recruit, retain, and develop the best team in the history of our industry and increase the diversity in our leadership at every level of our company. Strengthening the pipeline of diverse talent up to the executive level makes us a stronger, smarter, and better company. CULTURE We will maintain a company culture of respect and inclusion, where each individual can contribute and innovate to deliver the best customer experience. BRAND We seek to remain steadfast in advocating for all communities by doing our part to eradicate the homework gap for students and helping enable everyone to have access to connectivity. We also support educational and upskilling opportunities that will help make the 5G era, and the digital economy, more equitable. IN CONVERSATION WITH HOLLI MARTINEZ, VICE PRESIDENT OF DIVERSITY, EQUITY & INCLUSION Q. How do you help ensure DE&I continues to be rooted in T-Mobile’s culture? Embedding DE&I into our culture involves grounding and customizing DE&I initiatives into each line of business strategy. Our Equity In Action pillars of Talent, Culture, and Brand objectives and key results are aligned to business goals, ERG strategy, and throughout our local DE&I Chapters. This allows us to streamline DE&I behaviors and practices while addressing the unique business and local needs. We continue to focus on creating a more diverse and inclusive workplace by investing in efforts that give all our employees the opportunity to become involved— from building greater diversity into leadership functions across the company to empowering ERGs to focus on the dimensions of inclusion most relevant to our employees and their communities. Q. What have been some of the most successful ways your team has engaged and partnered with stakeholders on DE&I initiatives? Engagement and advocacy start with listening. Whether it’s business, people, or customer pain points, the best solutions come from these perspectives. We are proud of ensuring our employees are heard and act to make sure their needs are met and exceeded. Our Inclusion Council leaders are advocates for employee pain points and DE&I initiatives, elevating employee voices and employee engagement. Q. What are some of the key challenges to advancing DE&I efforts and how do you see T-Mobile addressing them? The biggest challenge DE&I faces is polarized discourse in our society. We must focus on what unites us rather than what divides us in order to create the culture of respect required to unlock the creativity and innovation born from our differences. At T-Mobile, we have never been afraid to have hard conversations. Whether it’s Talking with Trailblazers, team discussions, or open forums, we face real issues head on. We are Team Magenta, One Team passionate about connecting people to their world. Q. Tell us about a recent achievement in this space that you are most proud of. I am most proud of the accomplishments through the advocacy of our ERGs. When our Women and Allies Network pointed out gaps in our benefits for family planning and conception, we addressed those pain points with increased benefits. When our Veterans and Allies group identified a pain point with military spouses, we fixed it. When our Pride and Allies group called out a need for enhanced surrogacy benefits, we increased them. What I am most proud of is that DE&I is not a campaign, a slogan, or a window dressing. DE&I is authentic advocacy for equity for our employees, customers, suppliers, and communities. 2021 CORPORATE RESPONSIBILITY REPORT 29 OUR COMPANY THE NUMBERS AND SMALL PRINT OUR COMMUNITIES OUR GOVERNANCE OUR PEOPLE THE ENVIRONMENT

Diversity, Equity, and Inclusion Continued 27 On track with 27 out of 54 DE&I Promises achieved so far Delivering on Our DE&I Promises As part of our EIA plan, we made 54 DE&I Promises that s pan the investments we make in our employees, the products and services we offer, the suppliers we do business with, and the communities we advocate for. We’re proud to have achieved 27 Promises so far and are on track with several actions and efforts to deliver on the remaining 27. Some examples of the promises we’ve delivered on i nclude: ■ Established an External Diversity & Inclusion Council and a California Council ■ Added diverse representation to T-Mobile’s Board of Directors ■ Expanded access to wireless service through organizations serving underserved communities ■ Established partnerships with minority-owned banks ■ Increased procurement activities with diverse businesses Establishing Key Partnerships Our commitment to embed DE&I into every aspect of o ur company is ambitious, and we know that we can’t do it alone, which is why we leverage partners inside and outside of T-Mobile to help us achieve our goals. Our External Diversity & Inclusion Council is one of our m ost important allies and partners in our DE&I journey. Made up of leading thinkers and advocates in the space, the Council helps us identify ways to support our goals and provides important context and feedback as we im plement our EIA plan. Internally, we have an Inclusion Council comprised o f leaders from across T-Mobile working to drive awareness, spark conversation, host community events, and encourage all employees to be exactly who or what they want to be. We also have a Leadership Task Force and an Internal Oversight Committee that provide strategic input and connect actions across the company that help drive our EIA plan. Programs Driving Progress Creating impactful programs for our employees and c ommunities is central to our EIA plan. Our award-winning Talking with Trailblazers s peaker series fosters courageous conversations with employees on topics impacting society by elevating the voices of diverse leaders from both inside and outside our company. In 2021, we hosted 11 conversations that included Black h istory and Black excellence with artist and activist Common, authenticity in the face of discrimination with former NFL Coach Katie Sowers, taking a stand on racism with actor and producer Daniel Dae Kim, prioritizing mental health with psychiatrist Dr. Jess Clemons, and elevating LGBTQ+ voices and experiences with Laverne Cox, to name a few. In total, more than 24,000 employees engaged with our Talking with Trailblazers series throughout the year. We also launched an enterprise-wide training called t he One Team, Together Learning Journey which takes employees through an expansive, multi-year experience to help them form more inclusive habits in the workplace. The training was developed with the NeuroLeadership Institute and infuses DE&I into how we work at T-Mobile. It’s designed to strengthen the habits and behaviors we need to empower each other, build connections and belonging, and inspire winning, together. Last but not least, we launched our Magenta Scholars p rogram in 2021 in partnership with the Thurgood Marshall College Fund (TMCF) to provide educational opportunities to students attending historically Black colleges and universities (HBCUs). This collaboration, which started with an investment of $500,000 for 18 scholarships, has grown to $3 million in support from T-Mobile, spanning both scholarships and the new National Black Talent Bank program. TMCF’s Magenta Scholars have an impressive 85% graduation rate— more than double the national graduation rate for Black students overall. Scholarship recipients will also have an opportunity to join the Un-carrier’s signature summer internship program and receive mentorship and professional development opportunities. 500% increased investment in Magenta Scholars from $500K to $3M 2021 DE&I Distinction Ranked in Forbes/Statista’s America’s Best Employers for Diversity list Recognized by Reuters Responsible B usiness Awards for DE&I 100% score received on the Human Rights Campaign’s Corporate Equality Index for issues relating to LGBTQ+ employees, for the ninth year running 2021 CORPORATE RESPONSIBILITY REPORT OUR COMMUNITIES THE NUMBERS AND SMALL PRINT 30 OUR COMPANY THE ENVIRONMENT OUR GOVERNANCE OUR PEOPLE

OUR COMPANY OUR G OVERNANCE OUR PE OPLE OUR C OMMUNITIES THE E NVIRONMENT THE NUMBERS A ND SMALL PRINT Commitment to Pay Equity T-Mobile is committed to being an equitable and in clusive company in which we provide the best experience and opportunities for all our employees. Part of this commitment is to ensure that across all our business operations, our employees are paid equitably based on their work, regardless of gender, race/ethnicity, or other aspects of an employee’s identity not relevant to their work performance. Putting people first and treating them right is core to our va lues and how we operate. That’s why we embed principles and practices of equity in compensation packages (base salaries, bonuses, PTO, etc.) from the outset while considering factors such as market data, employee’s role and experience, job location, and performance. T-Mobile evaluates and benchmarks our compensation p rogram on an annual basis specific to regions in which we do business. Knowledge and best practices gained from these inputs are used to ensure that as we continue to evolve, all practices related to compensation will be in alignment with our broader commitments around putting diversity, equity, and inclusion at the center of everything we do for our employees, our customers, and our communities. Employee-Led Diversity T-Mobile’s ERGs started as a grassroots movement. Now, they’re an important element of our culture with nearly 40% of employees participating in one or more ERG. Our six ERGs and four sub-affinity groups drive actions to solve business and employee pain points, amplify and celebrate the rich diversity of our employees’ culture, heritage, and experience. They help foster a sense of belonging by sparking conversations, provide formal and informal opportunities to practice and develop leadership skills, and play a consultant role to the business. The members of our ERGs are dedicated to using their knowledge, experience, passion, and compassion to make a difference in themselves, the community, and our company. Celebrating Our Freedoms Starting in 2021, T-Mobile recognized Juneteenth as a n annual company holiday. We are proud to officially recognize this truly momentous American milestone, and feedback from our Black Empowerment Network ERG helped to bring about this change. 50+ DE&I Chapters. This is where DE&I comes to life: where local advocates address business and people pain points, driving initiatives that are personal and applicable to their local teams and communities. T-Mobile ERGs Accessibility Community at T- M ob ile Multigenerational Network Veterans & Allies Network Asia Pacific & Allies Network Indigenous Peoples Network Multicultural Alliance PRIDE Women & Allies Network Black Empowerment Network Magenta Latinx Network Diversity, Equity, and Inclusion Continued 2021 CORPORATE RESPONSIBILITY REPORT 31

OUR COMPANY OUR G OVERNANCE OUR PE OPLE OUR C OMMUNITIES THE E NVIRONMENT THE NUMBERS A ND SMALL PRINT PROGRESS 2021 2023 0 10,000 Military Hires Diversity, Equity, and Inclusion Continued Joining Forces on a Military Hiring Mission We’re inspired every month of the year b y the dedication and sacrifice of those in uniform. And we honor the families who support them, relocate with them, and serve alongside them. With their unique perspectives and powerful skill sets, our military team members are high performers and strong leaders. They understand the values that make us unstoppable together. It’s why we made a promise to hire 1 0,000 veterans and military spouses by 2023. At the end of 2021, we reached 69% of our goal and were once again designated by Military Friendly® as a top Military Friendly Employer and Military Spouse Friendly employer. 69% To continue advancing toward this goal, we’re reaching out at hundreds of job fairs and Veterans Affairs offices across the country. We’re also partnering with not-for- profit organizations such as Hiring our Heroes, FourBlock, and Warriors4Wireless to help fund career readiness programs and community support initiatives. T-Mobile also expanded our successful TechX Returnship Program to include veterans. TechX Returnship is a partnership with reacHIRE and helps facilitate paths to leadership roles for women—and now veterans— returning to the workforce in technology roles. The program provides opportunities to those with tech-centric resumes who’ve taken a long professional career break to care for family members, raise children, or to serve in the military. 2021 CORPORATE RESPONSIBILITY REPORT 32

OUR COMPANY OUR GOVER NANCE OUR PEOPLE O UR COMMUN ITIES THE ENVIRON MENT THE NUMBERS AND S MALL PRINT DE&I by the Numbers Transparency drives accountability and we are committed to being transparent with our employee diversity metrics and holding ourselves accountable for improving as we progress on our DE&I journey. Additionally, for the first time, we published our Federal EEO-1 Report . We’re proud of the progress we’ve made so far, while acknowledging that we still have room to improve as we press forward to create a more diversified and inclusive workforce that supports equal opportunities regardless of age, race, gender, ethnicity, color, sexual orientation, gender identity or expression, national origin, veteran or disability status. American Indian or Alaska Native Asian Black or Afric an American Hispanic or Lat ino Native Hawai ian or Other Pacific Islander Two or More Rac es Undeclared White T-Mobile U.S. Race/Ethnicity by Position Executive 0.3% 11.4% 4.8% 5.5% 0.2% 2.3% 0.2% 75.3% People Manager 0.6% 8.3% 14.6% 22.0% 0.6% 3.5% 0.1% 50.3% Individual Contributor 0.5% 9. 7 % 18.7% 2 7. 6% 0.4% 4.6% 0.2% 38.2% Grand Total 0.5% 9. 6% 18.0% 26. 6 % 0.5 % 4.4% 0.2% 40.3% Female Male Undeclared T-Mobile U.S. Gender by Position Executive 33.8% 6 6 .1% 0.1% People Manager 35.8% 64.2% 0.0% Individual Contributor 41.7% 58.2% 0.1% Grand Total 40.9% 5 9.1 % 0.1% All data is as of December 31, 2021; percentages by category may not add up to 100% due to rounding. 2021 T-Mobile U.S. Workforce Demographics 3,26 0 veterans * 4,28 3 individuals with disabilities * 2,292 LGBTQ+* T-Mobile Total U.S. Workforce—Gender 40.9% 5 9.1 % Male Female T-Mobile Total U.S. Workforce—Race/Ethnicity Diversity, Equity, and Inclusion Continued 5 9. 5 % 40.3% 2021 CORPORATE RESPONSIBILITY REPORT 33 White People of color *As self-identified as of 12/31/2021.

OUR COMPANY OUR GOVERNANCE OUR PE OPLE OUR C OMMUNITIES THE E NVIRONMENT THE NUMBERS A ND SMALL PRINT “Second Best” Experiences Aren’t Good Enough Ensuring everyone enjoys equal access to our products, services, and mobile experiences is paramount to our DE&I commitments. And that’s as true for our employees as it is for our customers. Our dedicated Accessibility Resource Center (ARC) focuses on removing barriers in the digital space. In partnership with our DE&I team, they have continued to address enterprise-wide digital systems and tools to help improve the online experience for our customers and employees with disabilities. It’s our priority to ensure that nothing is “second best” when it comes to ensuring that our digital experience meets the needs of all our employees and customers. In tandem with this work, nearly 30,000 Customer C are employees have undergone Accessibility Cultural Awareness training to help them better assist our customers with disabilities. Additionally, T-Mobile offers accessibility options for c ustomers such as alternate billing for individuals with visual impairments, free credits toward 411 directory services, RTT (real-time text), and easy-to-use handsets. T-Mobile is also the nation’s largest provider of T elecommunications Relay Services, enabling those with speech disabilities and hearing loss to communicate over the phone by using a specialized text telephone and operator service to convert voice communication into text. From store designs to office layouts and user experience ( UX) design, our teams aim to create environments, products, and services that empower and engage employees and customers, creating the opportunity to thrive regardless of their needs or abilities. All Access for All Employees As an inclusive employer, we want every employee to h ave an equally rich experience at T-Mobile and be able to fully participate in our suite of programs, resources, and events. From staff meetings and all-employee events, to participating in our first-ever Accessibility Summit, optional wellness webinars, and ERGs, we believe everyone should be equally able to follow proceedings and contribute. We provide reasonable accommodations such as American Sign Language interpreters, captioning, and audio descriptions for every employee or candidate who indicates they need them. Listening Helps Us Learn In 2021 we started hosting listening sessions in c ollaboration with our ERGs, inviting employees with disabilities to have an open discussion about current initiatives. These sessions provide an important space for productive dialogue and feedback and allow us to unlock wisdom and ideas from across our employee base. Diversity, Equity, and Inclusion Continued 2021 CORPORATE RESPONSIBILITY REPORT 34 Partnering on Our Accessibility Journey Our external partnerships help us keep up with e volving accessibility trends and resources. Along with industry peers, we participate in working groups run by Disability:IN, a non-profit resource for business disability inclusion worldwide. This gives us the opportunity to work directly with subject matter experts and further enhance our own skills and programs. We also partner with the American Association for P eople with Disabilities (AAPD), a U.S.-based non-profit that advocates for Americans with disabilities. In 2021, we served for the first time as host company for one of their interns. And, we were recognized as a Leading Disability Employer by the National Organization on Disability. 2021 Accessibility at a Glance 100% T-Mobile’s score on Disability:IN’s Disability Equality Index for the fifth year running ~30,000 Customer Care employees have taken our Accessibility Cultural Awareness training 50% increase in American Sign Language interpreting staff * support *measured by FTE Leading Disability Employer designation from the National Organization on Disability

OUR COMPANY OUR GOVERNANCE OUR PE OPLE OUR C OMMUNITIES THE E NVIRONMENT THE NUMBERS A ND SMALL PRINT Employee Engagement, Learning, and Development We Won’t Stop Learning T-Mobile is known as a great place to advance and grow your career. That’s thanks in part to the robust training and career exploration opportunities we offer to all levels and functions throughout the company. Our lineup of development programs and resources was created to build a diverse group of leaders and empower our people to succeed through every step of their career. And it’s all easily accessible on our Magenta University site, which is our one-stop shop for all things career development and learning. The online learning portal is designed to put employees in the driver’s seat and give them access to mentoring, training, videos, books, job search and interview tips, and much more. 2021 Learning and Development Highlights Our CareerFest event, a chance to explore career opportunities around T-Mobile, reached more than 8,700 employees The Apprenticeship program had a 100% conversion rate into non-apprentice T-Mobile roles for those who completed the program Employees participated in over 5.4 million hours of training * * Only includes trackable training hours completed i n our formal Learning Management System by full-time and part-time employees. 15,700 employees took part in our Day of Learning (and rated it 4.3 out of 5 stars) Lead Magenta Next a w ar ded the i4cp Next Practice Award Named in the 2021 LinkedIn Top Companies list for best workplaces to grow your career 2021 CORPORATE RESPONSIBILITY REPORT 35

Employee Engagement, Learning, and Development Continued OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT By strategically investing in four key areas of career development and learning, we’re building a diverse group of strong leaders now and for the future. Evolving Skills and Careers We’re champions of constant, lifelong improvement ―regardless of career stage. For instance, our new Apprenticeship Program creates pathways for those without advanced degrees or experience. In 2021, the first cohort of apprentices began a 12-month journey to build their skills through classroom instruction, hands-on experience, and mentorship. The program offered apprenticeships in four roles—Associate Trainer, Analyst Business Support, Associate Expert, and Associate Systems Administrator. All the apprentices who completed the program went on to take jobs with us. Apprentice Francia Mesa said: I wouldn’t have qualified for a Sr. Business Analyst role if it wasn’t for the apprenticeship program. This program provided me the opportunity to learn new skills like Excel, SQL, and project management. The apprenticeship program equipped me with the knowledge I needed to be successful in my role and the ability to better support the frontline teams.” For T-Mobile employees, we have an enterprise rotational program called CareerTrax to provide opportunities to gain experience in different parts of the business. Performance and Development Feedback is foundational to performance improvement and career development. However, it’s most effective when conversations happen all year long. Programs like Accelerate My Performance (AMP) equip employees and managers with resources to have productive, ongoing development conversations. Employees also create Individual Development Plans (IDP) to help them assess and develop identified Values in Action and other behaviors with their manager’s support. Making connections that count can also help employees develop their skills so we added Mentor Match and Executive Sponsorship to our development programs in 2021. Mentor Match connects employees to a mentor for career guidance, to diversify their network, and gain new knowledge and skills. The Executive Sponsorship program helps select Directors and Sr. Directors establish a formal sponsorship relationship with a VP or SVP in another line of business with the goal of accelerating their careers, expanding their network, and giving executives broader visibility of our diverse talent across T-Mobile. Championing DE&I DE&I is central to the design of our career development and learning opportunities. Programs like our One Te a m , Together Learning Journey promote inclusive habits and behaviors at every level of the organization, while targeted programs like Lead Magenta Next help develop underrepresented talent and strengthen diversity at the leadership level. In 2021 we partnered with McKinsey to deliver two programs that enhance the capabilities of underrepresented leaders. The McKinsey Manager Accelerator focuses on enhancing leadership mindsets and behaviors and deepens participant understanding of nine business topics. The McKinsey Executive Leadership Program equips future leaders with the peer network and sponsorship that helps them achieve their aspirations as well as develop new capabilities, mindsets, and behaviors. India Boulton, Senior Vice President, Legal Affairs, T-Mobile, said: The transition into the executive space specifically as a person of color wasn’t something that was taught to me in law school or during my corporate experience. This program lifted the veil on additional skills that I needed to navigate my career trajectory and provided me a network of leaders who looked like me and had overcome similar obstacles in organizational management and their pursuit of leadership opportunities.” Advancing Leadership Expertise We want to develop and inspire great leaders across the company by helping employees unlock their potential and build critical skills to thrive as their responsibilities grow. In 2021, we enhanced our leadership development programs to further empower existing and future leaders to grow in their careers through confidence. We added LeaderShift , a leadership development program for employees who want to SHIFT to the next level. This program was designed to grow the employee’s confidence and foster career growth through supported, personalized leadership development that helps them make an impact on their teams and the business. We also launched Magenta Manager , which provides people managers with learning experience options to enhance their effectiveness and skills and foster a community and culture of leadership. 2021 CORPORATE RESPONSIBILITY REPORT 36

OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT Feature Story: Learning and Development DEVELOPING NEW PATHWAYS FOR DIVERSE LEADERSHIP In this new era of Un-carrier, we’re doubling down on our commitment to cultivate a culture of belonging. We do this by listening to our employees, creating career development programs centered on DE&I, and by addressing barriers underrepresented talent face at critical points in their careers. At T-Mobile, it’s important we open new pathways for development and increase leadership diversity across the company. More Than Mentorship Our Lead Magenta Next (LMN) leadership development program is aimed at putting underrepresented talent at the intersection of sponsorship, readiness, and opportunity. Sponsored by T-Mobile’s ERGs and designed with their guidance, LMN participants can be nominated by anyone in the company, including themselves, a feature that helps mitigate potential bias. The program also prioritizes sponsorship to help women and people of color build a network of advocates. By nurturing these relationships, LMN opens avenues for new partnerships across the enterprise, connects program participants to new opportunities, and brings together diverse groups of employees for innovative, authentic growth. A Support Team Around Each Participant The level of support provided to the 25-person cohorts is one reason the program has been so successful. A Personal Advisory Board is built around each participant and includes an internal mentor to guide them through the stretch assignment, an external mentor to assist with individual development planning, an executive sponsor to open networks and advocate, an internal executive recruiter to provide insight into hiring, and the participant’s manager to support engagement in the program. “You get an external executive coach, and to me that was unique,” said Monic Payne, who participated in the program and is now a Director Product, Portfolio & Sourcing at T-Mobile. “Having this outside perspective really helped me to grow and look at things from a different view. Through this journey with Lead Magenta Next, I had the opportunity to apply for a director position. I called my internal executive sponsor and received guidance from my external executive coach during the process.” Launched in 2020, this program is already seeing results with 28% of the participants being promoted within two months of completing the program. Sponsorship was reported as a key factor in gaining their promotions. 28% of the first Lead Magenta Next cohort were promoted within two months of completing the program LMN was recognized by the Institute for Corporate Productivity (i4cp), a leading global human capital research firm, and named the i4cp Next Practice winner in 2021. i4cp Next Practice Awards recognize companies that are leading the way in HR, talent, and workforce innovation. This recognition is a testament to the impact the program is already having on driving development opportunities and diversity in our leadership. We are so lucky to have had the opportunity to participate in Lead Magenta Next and present our concept to leaders... Not only did they understand the vision, but they incorporated it into their already amazing roadmap and expanded our concept even further. Can’t wait to see what new ideas and concepts come from the next generation of LMN leaders!” Lawrence Garcia Sr. Business Development Manager, Ru ral Consumer Group, MCA 2020 2021 CORPORATE RESPONSIBILITY REPORT 37

OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT Health, Safety, and Wellness Benefits Tailored to Our Employees Our employees take care of our customers, and we want to take care of them! All of our part-time and full-time employees— from frontline to executives to back-office employees—have access to the same offerings, including health benefits . v In 2021, we enhanced a range of benefits across the company to meet the diverse needs of our employees —from mental health benefits to higher hourly wages and family planning and reproductive health services. A Focus on Our Frontline It takes mastery and commitment to be part of the best customer care and retail team in the history of wireless. Today, T-Mobile frontline staff support not only our wireless, wireline, and accessibility businesses, but also emerging products and services divisions. To reflect the growing expectations and experience required of our frontline teams, we implemented a nationwide minimum pay of at least $20 per hour. This applies to every single employee regardless of role, or full-time or part-time status. And with total compensation—such as 401K matching and generous stock options—factored in, our starting hourly rate for all employees effectively rose to over $22 per hour. Specific to our care team, this represents an increase in total compensation up to 19% for over 12,000 members. Helping resolve customer pain points is hard work! So we added 15-minute paid wellness breaks to the daily schedule of all customer experience center staff in 2021. Coupled with programs like our Parent Forums and financial literacy courses, our wellness initiatives help ensure our employees feel supported and equipped to tackle challenges inside and outside of the workplace. Helping People Stay Safe Through the Pandemic We continue to navigate the pandemic together— as One Team—and have implemented various measures to keep our T-Mobile community—our employees, our families, and our customers—safe. It’s been a journey, to say the least, and we’ve been inspired by our employees’ resilience, commitment, and passion in these truly unprecedented times. Information about health and safety resources and policy changes is communicated to all employees regularly through multiple channels, including our Stay Healthy Together internal website. This centralized hub provides the latest updates related to COVID-19, resources to support employees, and guidance to help us all work toward a new, better normal. We also continued our educational series, COVID Connect, with Dr. Vin Gupta, a Critical Care Pulmonologist and Assistant Professor of Health Metrics Sciences at the University of Washington. The series fosters ongoing conversations with a credentialed health expert and our employees on key COVID-related topics. T-Mobile also works closely with Dr. Gupta on options and critical decisions for our business to keep our employees, customers, and communities safe. 2021 Employee Benefits Highlights Increased free mental health visits from 5 to 10 on a per incident (not per year) basis Rolled out new benefits in response to employee requests, including up to three weeks paid leave to care for a family member Launched a diabetes program that includes personal diabetes coaching and free equipment in response to worsening diabetes through the pandemic Improved our short-term disability coverage and bonding periods related to childbirth Offered benefits that address a wide range of family planning and reproductive health services Made big changes to our prescription benefits, including adding an innovative program that provides specialty medications at no cost to the employee, which are often prohibitively expensive Partnered with healthcare providers to roll out a broader set of services via virtual care , at lower cost to employees Enabled employees to purchase long-term care plans in case they need it later in life Included in Comparably’s Best Perks and Benefits list for four consecutive years v Excludes interns who are classified as temporary employees. 2021 CORPORATE RESPONSIBILITY REPORT 38

OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT Health, Safety, and Wellness Continued Removing Barriers T-Mobile is committed to removing barriers for employees to access our benefits whenever possible. For example, we pay tuition expenses up front for employees wishing to further their education, making it easier to attend school on a part-time basis by not having to worry about fronting out-of-pocket costs. It’s also why we’re constantly evolving current benefits to better meet the needs of our employee base. ~$20.2M paid in tuition assistance for more than 5,500 employees In January 2022, we enhanced our employee assistance program even further to ensure the clinicians taking calls better represent the demographics of ALL of our employees. COMPANY OWNERSHIP CREATES A DIFFERENT MINDSET Every member of our team is given the opportunity to be an owner of the company. Since 2014, we have awarded annual restricted stock unit grants to eligible employees at every level of the company so that everyone can truly share in T-Mobile’s performance. We also offer an employee stock purchase program, where employees can purchase TMUS stock at a 15% discount through payroll deduction. Rethinking a Renovation in Real Time 2021 CORPORATE RESPONSIBILITY REPORT 39 When COVID-19 began sweeping the world, T-Mobile had to pivot its ambitious renovation plans for our headquarters in Bellevue, WA and Overland Park, KS to incorporate the enhanced safety measures we knew would become commonplace in a post-pandemic world. Darcey Estes, Vice President, Corporate Real Estate, and her team got to work searching for ways to mesh her goal of creating inspiring spaces with a heightened emphasis on creating the safest environments possible during a pandemic. Heating, ventilation and air-conditioning (HVAC) systems were upgraded to maximize filtration in all buildings and MERV 13 filters were installed in all buildings (where mechanically feasible). Incredible new co-working spaces, high-tech conference rooms, creative social spaces, and top-of-the line amenities were enhanced to integrate COVID-19 health and safety features like social distancing signage, capacity limits, sanitation stations, and contactless building features. Not only did Estes’ team pivot mid- stride to rethink headquarter office renovations, they also worked to get all regional corporate office locations and 24 customer experience centers, in addition to the Bellevue and Overland Park headquarters, certified through the WELL Health-Safety rating, a first for our industry. The rating was created by the International WELL Building Institute, the global authority on healthy buildings, and incorporates guidance from more than 600 public health experts from around the world. Estes says, “Since the very early days of the pandemic, T-Mobile has been focused on doing everything we can to ensure our customers and employees feel healthy and supported when they step into any of our spaces, and this WELL Health-Safety rating reflects our immense dedication to those efforts.” Thanks to this work, T-Mobile spaces are both inspiring and safe, reflecting our commitment to employee and customer health and safety. It’s just one more reason why T-Mobile is a great place to work.

2021 CORPORATE RESPONSIBILITY REPORT OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT 40 DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT DIGITAL EMPOWERMENT OUR COMMUNITIES DIGITAL EMPOWERMENT

OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT Our Communities Connectivity is essential in our daily lives. The global pandemic over the past two years has been a powerful reminder of the increasingly critical role connectivity plays in our daily lives—from accessing education, healthcare, jobs, and social services, to staying in contact with loved ones and the world around us. T-Mobile is passionate about enabling everyone to have access to the connectivity, technology, and skills needed to thrive in a digital world. From supporting community partners to investing in education initiatives and providing disaster relief, our focus is on empowering people with the tools they need to make their essential connections. 2021 Highlights 3.2M students connected through Project 10Million education programs 94% of Americans covered by our Extended Range 5G network ~$1.89B provided in funding and in-kind products and services to support communities Supported nearly 1,500 school districts through Project 10Million e 5 mp 2 loy , ee v 000 olunteer hours In e n s 75 v sted i mall towns across America through our Hometown Grants program 2021 CORPORATE RESPONSIBILITY REPORT 41 8,000+ non-profits and community organizations supported

OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT Feature Story: Digital Equity 3.2M STUDENTS CONNECTED AND COUNTING Connectivity has become a baseline requirement for accessing the opportunities, resources, and information needed to thrive in our hyper-connected world. And nowhere is this more true than in education―the great social leveler―where students without reliable connectivity are at a clear disadvantage. 2021 CORPORATE RESPONSIBILITY REPORT 42 That’s why, in 2020, T-Mobile launched Project 10Million, our $10.7 billion commitment to end the digital divide in education. Project 10Million provides free internet service and free mobile hotspots to under-connected households with school-aged children, aiming to reach up to 10 million eligible households over five years. Individual families with qualifying students can sign up directly online. We also reach students by partnering with schools. The program also offers school districts free and highly subsidized data plans that they can provide to their students for free, as well as access to affordable laptops and tablets. Through our education initiatives, we’ve connected 3.2 million students through the end of 2021—and we’re not stopping there. Working with Schools to Close the Gaps We have worked with thousands of school districts across the country to identify where access to connectivity is needed most to get students enrolled into the program. We couldn’t be prouder of the impact we’ve had! For example, in March 2020, just 12% of the 35,000 students in Oakland Unified School District (OUSD) in Oakland, CA, had adequate connectivity at home. And while an emergency donation enabled many of them to have tablets and laptops, they couldn’t do much without connectivity. Through Project 10Million, T-Mobile quickly provided hotspot connectivity to the district’s students and within a few months, 98% of the school district’s students were connected. In Chicago, T-Mobile partnered with city officials to identify and connect more than 26,000 student households in underserved communities to help get these kids the right tools to compete academically. And in Miami-Dade, FL we continue to partner with educators to understand critical needs and where Project 10Million can have the greatest impact. As part of these efforts, we distributed 5,000 hotspots in one day and are working to connect almost 35,000 students. Leveraging this education expertise to work hand-in-hand with school district leadership teams has allowed us to expand the conversation beyond access and into the core of impactful student learning outcomes as a result of student internet access. These vital industry relationships support greater device adoption, scalable connectivity solutions, and more sustainable implementation of student connectivity programs.” Dr. Kiesha King Sr. National Education Administrator, T-Mobile Collaborating and partnering with educators both outside and within T-Mobile has been an impactful feature of the program. Our in-house staff of education administrators have experience in navigating both the education system and the classroom. While we’ve made huge strides toward bridging the digital divide and advocating for universal connectivity, there’s still more to do to ensure all students have the opportunity―and technology―to thrive. As we look ahead, we’re working to leverage partnerships with school districts, non-profits, and local officials across the country to expand Project 10Million’s reach.

OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT The T-Mobile Project 10Million has had a major impact on the students in our district. Brocton Central School is a small rural district with some areas where high speed internet is not possible through the typical means via cable, fiber, or DSL, due to geographic location. The district has been struggling to find funds to supply our students with internet in our community for remote instruction and access to online resources. With Project 10Million we have been able to connect those students and families with hotspots which have been critical for learning during the pandemic. Even as we have transitioned back to in-person learning, an internet connection is a necessity for today’s classrooms to prepare students for higher learning and their future workplaces.” Michael Schultz Director of Technology and Communications & Chief Data Privacy Officer, Brocton Central School, NY PROJECT 10MILLION IMPACT STORIES Education is essential, it ensures the future of our communities and our country. However, it only works when all students have the same access to instruction regardless of their demographic circumstances. T-Mobile safeguarded our ability to provide equity and inclusion to all of our families through Project 10Million. My team and the entire Borough of Middlesex are infinitely thankful for this. Helping people in their time of need is a rare quality in internet service providers.” Damien J. Dimino Technology Manager, Middlesex Borough School District, NJ For many of our students and their families, internet access is not only about access to educational resources, but a lifeline to online telehealth services, job exploration resources, or safety net programs. When we decided to accelerate and expand our efforts to provide our students and their families with reliable internet connectivity at home, T-Mobile and Project 10Million were the obvious choice for us to partner with. What we needed was a partner who not only understood our needs, but who would align their goals with ours and be mutually invested in our mission. We know our work isn’t done yet, but T-Mobile and Project 10Million are committed to continue working with us until access to reliable internet is a reality for all students of Miami-Dade County Public Schools.” Sylvia J. Diaz Chief Academic Officer, Miami-Dade County Public Schools, FL 2021 CORPORATE RESPONSIBILITY REPORT 43 Feature Story: Digital Equity Continued

OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT Digital Equity ACCESS AND AFFORDABILITY Ensuring that everyone thrives in a digital world means starting with access to affordable, available, and reliable connectivity. Beyond investing in programs like Project 10Million, T-Mobile has been rapidly building out our network to deliver the broadest and deepest 5G experience across the country—including rural areas—while providing more affordable options to families with limited incomes to support a more connected, digitally equitable future. Because no one should be left behind when it comes to connectivity—regardless of their economic circumstance or their ZIP code. CONNECT BY T-MOBILE: A PLAN MILLIONS MORE CAN AFFORD Delivering on our promise to make connectivity more accessible, Connect by T-Mobile helps close the digital divide by putting connectivity within easy reach of more people. The plan provides a low-cost option to help connect millions of low-income families and individuals—because no one should have to choose between staying connected and paying for other basic necessities. HIGH SPEED INTERNET THAT REACHES PLACES FIBER OPTICS CAN’T America’s vastness is a beautiful thing―unless you are installing broadband. Running a fiber connection to every home in the country is economically unfeasible, which leaves nearly 15% of households with only one choice for home broadband; in rural areas that jumps to nearly 35% vi . T-Mobile’s High Speed Internet changes that. When launched in April 2021, more than 30 million households were eligible for our service, including 10 million in rural America, turning T-Mobile into one of the largest broadband providers in the U.S. by service area. Access quickly expanded to more homes across the Southeast, Texas, Indiana, Kentucky, and Ohio, and continues to grow rapidly as our 5G coverage grows. 30 househol M ds eligible for our service at time of launch GOING ALL IN ON SMALL-TOWN AMERICA T-Mobile is going ALL IN to be the leader in America’s underserved smaller markets and rural areas. At the end of 2021, our 5G network spanned 1.8 million square miles, with 1.45 million of that covering small town America. As our network expansion continues, we plan to reach 99% of Americans with 5G by the end of 2023. This is where our network leadership stands out, as we’re the only 5G game in town for many of these communities. For more details on how we help smaller towns across America thrive, see the story on Hometown Grants . CONNECTING OUR HEROES We count on first responders, and they can count on us. We’re proud to offer our groundbreaking Connecting Heroes program, a 10-year commitment to provide free service and 5G access to first responder agencies—all public and non-profit state and local fire, 911, police and EMS departments—saving them up to $7 billion vii . In 2021, T-Mobile made enhancements to the program, including priority access AND preemption for both voice calls and data for first responders enrolled in the Wireless Priority Service (WPS) program. So not only do first responders get to the front of the line at T-Mobile, but if the network ever becomes crowded in an emergency, non-emergency traffic drops to make way for first responders’ critical communications. vi Highspeedinternet.com Why Can I Only Get a Few Internet Providers? | HighSpeedInternet.com vii Estimated savings if every department takes advantage of the program. 2021 CORPORATE RESPONSIBILITY REPORT 44

OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT Investing in a More Digitally Inclusive Society Access to connectivity is no longer enough in our digital world. Most aspects of daily life require the ability to navigate the internet proficiently and safely, from banking to civic engagement and finding employment. Furthermore, as digitization expands across all facets of the economy, those who lack the skills to compete are increasingly left behind. That’s why T-Mobile has begun to expand our focus on digital equity to include digital literacy and critical job skills needed to compete and thrive in the digital economy. Digital Equity Continued Digital literacy is just as important as connectivity. Every day, as well as widening access to our network, T-Mobile supports digital literacy programs for people who face the highest barriers, including seniors, people of color, and people in rural areas.” Clint Odom Vice President for Policy and Advocacy, T-Mobile The Lewis Latimer Plan— a New Deal on Digital Inclusion T-Mobile is committed to fostering a digitally inclusive society and is a a supporter of the Lewis Latimer plan, a blueprint for digital equity for all that addresses four achievable goals: ■ Deploying networks everywhere ■ Getting everyone connected ■ Creating new economic opportunities to participate in the growth of the digital economy ■ Using the networks to improve the delivery of key services, particularly in workforce development, healthcare, and education Parts of the plan have been incorporated into the Infrastructure Investment and Jobs Act, with $2.75 billion allocated for the Digital Equity Act to help improve states’ and local governments’ digital inclusion efforts. The Act also introduced the federal government’s Affordable Connectivity Program (ACP), which subsidizes connectivity for eligible citizens. We are doing our part to keep more income-insecure households connected and broaden access to 5G for All. Metro by T-Mobile and Assurance Wireless® are participating in the ACP where eligible households receive a $30 monthly discount (up to $75 on qualifying tribal lands, as determined by the FCC) toward internet service on certain plans. We’re proud to be a leading wireless provider chosen by consumers participating in the ACP. Supporting Digital Literacy for Hispanic/Latino Communities As part of our Equity In Action plan, we have furthered our long-standing support of the country’s largest and most influential Hispanic/Latino advocacy organizations—the League of United Latin American Citizens (LULAC) and UnidosUS (formerly National Council of La Raza). According to McKinsey, Hispanic/Latino business owners and workers are more likely than other demographics to encounter barriers to digital reskilling and consequentially leaving them behind in digital opportunities. T-Mobile’s support of digital literacy aims to address inequities experienced by Hispanic/Latino students and business owners and bring digital literacy programs directly to growing Hispanic/Latino communities across the U.S. T-Mobile began supporting LULAC’s Conexiones program in 2021. Key pillars of the program include an introduction to digital privacy and security, using the internet to conduct research and to identify misinformation, combating cyberbullying, building a healthy self-image and digital reputation, and cultivating positive relationships online. 2021 CORPORATE RESPONSIBILITY REPORT 45 In 2021, we also supported the Unidos Latinx in Business program, which aims to help Hispanic/Latino business owners thrive in a digital world. Program participants learned how to use affordable technological solutions including 5G connectivity, digital payments, and budgeting apps to streamline their business operations. The Latinx in Business program also offers overviews on how to use email, social media, and texting to provide customer service, as well as timely information on COVID-19-specific federal aid programs for small businesses, and COVID-19 safety protocols.

Digital Equity Continued OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT Closing the Digital Divide in California In 2021, T-Mobile continued to honor our commitment to the California Emerging Technology Fund (CETF) for contributions earmarked for digital literacy training and other digital inclusion programs for low-income and unconnected Californians. Breaking Down Barriers and Creating Opportunities for LGBTQ+ Youth As a longstanding partner of the Human Rights Campaign (HRC), we made a five-year commitment to support the HRC Foundation as it launches a new initiative to provide digital literacy and financial empowerment training and resources for disadvantaged LGBTQ+ youth, helping this vulnerable population lead safer, healthier lives. The training includes education about cyberbullying and internet safety, as well as the basics of budgeting and financial management. HRC’s new programming will provide critical understanding and new skills that can help disadvantaged LGBTQ+ youth lead healthy, productive lives. Helping Entrepreneurs Build their Skills with Magenta Edge With Magenta Edge , the mission is simple: to help small business owners get ahead. Founded in early 2021 with a focus on Black-owned small businesses that have been disproportionately impacted by COVID-19, Magenta Edge serves as a hub of original content to help small business owners learn and execute as they navigate the ups and downs of entrepreneurship. Magenta Edge provides educational programming, real stories, and insight for all entrepreneurs, and covers a range of business topics, from marketing and communications to business finances and digital taxes. It has featured successful small businesses we love here at T-Mobile such as Abbey Creek Winery, BOOMBOX Gym, REC Philly, ZEN Succulent and Big Mama’s Kitchen (pictured below clockwise from top left). To see videos featuring these small businesses, visit the Magenta Edge website. Going forward, the program’s content will continue to evolve and expand with a focus on ALL minority- owned small businesses. 379K Unique visitors engaged in the Magenta Edge curriculum in 2021 21K signed up for digital workshops Digital Workshops A workshop series where small businesses receive advice and best practices on a variety of topics in sessions led by industry experts. Original Stories A documentary style mini-series exposing and highlighting the unique challenges Black-owned businesses face, exacerbated by COVID, and how they achieved success. Resource Center A small business content hub featuring original articles and learning materials powered by the Magenta Edge curriculum. EXTENDING A WELCOME TO REFUGEES WITH WELCOME.US Global unrest and conflict have created a massive refugee crisis. In countries like Afghanistan and Ukraine, families have been forced to leave their homes and begin the difficult process of rebuilding their lives in a new environment. For those who have left everything behind, connectivity is an essential lifeline to help them establish their new lives here in the U.S. That’s why, in early 2022, T-Mobile’s Mike Sievert joined 35 other CEOs from leading companies across business sectors to form the Welcome.US CEO Council. Through a unique public/private partnership model, newcomers to the U.S. are provided with urgently needed products, services, job training, and employment opportunities to help them begin their new lives. T-Mobile is contributing up to 200,000 lines of free, unlimited talk, text, and data for one year to help support incoming Afghan and Ukrainian refugees being resettled in the U.S. We are proud of this partnership and our contribution as it highlights the critical importance of our mission―to be the best in the world at connecting customers to their world. 2021 CORPORATE RESPONSIBILITY REPORT 46

OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT Philanthropy Giving Back the T-Mobile Way Our approach to philanthropy brings together our most valuable assets―our technology, scale, and employees―with the aspiration of creating a connected world where everyone can thrive. We focus our philanthropic investments in areas that advance digital empowerment and support employee- driven community engagement. This approach positions us to drive meaningful impact on societal issues that we can credibly and authentically influence while empowering our employees to give back to the causes most important to their hearts and their communities. Our work supporting our communities was recognized on PEOPLE’s 2021 100 Companies That Care list. In 2021, we donated more than $1.89 billion as a company and through the T-Mobile Foundation to communities across the U.S. and Puerto Rico. This represents $32.8 million in charitable donations from the T-Mobile Foundation and the business, and $1.86 billion through in-kind product and service donations including Project 10Million educational initiatives and disaster relief efforts. Empowering Employees to Give Back Nowhere is our magenta heart more visible than in the communities our employees call home. Through the T-Mobile Foundation, we empower our employees to volunteer and donate to the causes they care most about, matching up to $2,000 in donations or volunteer hours per calendar year. Because not everyone is able to volunteer or donate to the causes they hold dear, we seed employees’ giving accounts with funds that enables them to give back, on us, at select times throughout the year. Additionally, all new employees that join T-Mobile automatically receive giving funds as part of their welcome. In 2021, our employees showed up as an unstoppable force for good, personally donating nearly $3.7 million to local communities and volunteering over 52,000 hours of their time―despite continued constraints posed by COVID-19 restrictions. Changemaker Challenge: Finding the Ideas That Will Change the World T-Mobile searches for the changemakers of the future and helps them move forward with their world-changing ideas. The Changemaker Challenge is an annual nationwide contest that mobilizes the next generation to imagine and plan how to create positive change in their communities. In 2021, we brought in 15 teams of visionary teens to our headquarters in Bellevue, WA, for the three-day Changemaker Challenge Lab. The top teams in each category (Environment, Education, Technology, and Family Challenge) pitched their ideas to change the world to T-Mobile executives for the chance to win a $15,000 seed funding grand prize. Our senior leaders were so impressed they couldn’t choose just one winner. Instead, all four projects shared the prize: Technology Operation Serenity (Rochester, MN): An app that gives pediatric patients preparing for surgery peace of mind through kid-friendly simulations. Environment Aqua-Pods (San Jose, CA): A 100% plant-based, biodegradable sponge that combats water waste and leads to more fertile soil. Education Medicine Encompassed (North Brunswick, NJ): A student-run non-profit organization working to solve the problem of underrepresentation in medicine. Family Challenge Terracan (Bellevue, WA): A smart trash can and app that calculates your waste footprint to help reduce garbage. We can’t wait to see what new trails these young innovators will blaze in years to come. 2021 CORPORATE RESPONSIBILITY REPORT 47

Philanthropy Continued OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT GIVING BACK, TOGETHER Throughout the year, T-Mobile rallies employees across the company to give back, together. And, for an extra dose of goodness, we often invite our customers to join us. PAY AWAY T H E L AYAWAY For the second year in a row, we partnered with Pay Away the Layaway, an extraordinary non- profit organization that pays off layaway balances for people facing economic insecurity. Through the generosity of our employees and customers, we raised over $1 million in 2021 to pay layaway balances for military families and people in rural communities. 4 class , roo 7 m p 94 rojects funded DONORSCHOOSE We were proud to help support teachers across the nation through DonorsChoose, a national non-profit that enables individuals to donate directly to public school classroom projects. Together with our customers, we raised nearly $2 million to provide classrooms across the country with critically needed school supplies. As a new teacher in a low-income area I could never have done this without your help. My students and I thank you.” Ms. Middleton Grades PreK-2 | Peoria, IL DE&I GIVING MONTH We held our first-ever focused DE&I giving month where the T-Mobile Foundation distributed a $20,000 grant each to six charities hand-selected by our ERGs and hosted a 2:1 matching opportunity for all employees that donated to these six charities. Our employees engaged in record numbers, raising nearly $250,000, including a match from the T-Mobile Foundation. 2021 CORPORATE RESPONSIBILITY REPORT 48

OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT Hometown Grants: Revitalizing Small Towns Across the Country As part of our larger commitment to rural America and our aim to achieve 5G for All, we are committed to helping smaller towns across America thrive. In 2021, T-Mobile launched an innovative program focused on investing money and volunteer energy into the community projects that residents of small towns really care about. Hometown Grants is our five-year, $25 million commitment that awards up to $50,000 each to 25 different small towns every quarter through 2026. From revitalizing a historic theater to creating an arts and innovation incubator to renovating a shelter for abused women and their children, the Hometown Grant winners create amazing projects that bring long-lasting benefits to their communities. At the end of 2021, the Un-carrier had given more than $3.3 million to support projects that are bringing economic opportunity and other benefits to 75 small towns in 35 states. To make sure we direct funds in a way that transforms communities, we’ve partnered with Smart Growth America and Main Street America, two organizations with a combined 60+ years’ experience building resilient and prosperous small towns and rural communities. By collaborating with our partners and community stakeholders on the ground, we are building lasting relationships centered on trust and shared goals. Community Helping Community Take the town of Lake Orion, MI, from the first round of grant recipients announced in fall 2021. The community wanted to enhance one of its lakeside parks with a pavilion and playground equipment—and we wanted to help. In addition to our financial support, team members from our nearby retail store and local marketing teams rolled up their sleeves and assisted with construction during the one-day community build. Our village parks and recreation board has worked hard with very modest funding to provide continued improvements which in turn support our growing economy. Today, T-Mobile is helping us to launch a new adventure with new breath and freedom to build on new ideas. We look forward to the many great benefits that our community will have as a result of T-Mobile’s generosity.” Ken Van Portfliet Village Council President of Lake Orion Hometown Grants isn’t just about responsibility. It’s the kind of commitment that wins word-of-mouth recognition and earns long-term customer loyalty. Philanthropy Continued 2021 CORPORATE RESPONSIBILITY REPORT 49

OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT Disaster Relief When Disaster Strikes, Connecting People Is Our Priority Disasters wreak havoc when they strike, making connectivity paramount to first responders, local authorities, and impacted communities. We prepare year-round for disaster scenarios to be ready at a moment’s notice with critical network support and connectivity supplies. Thanks to our distributed model of warehouses around the country, we can quickly deploy supplies and our emergency management fleet, including satellite- enabled vehicles, mobile command centers, Cells on Wheels (COWs) and Cells on Light Trucks (COLTs), to impacted areas. Vehicles can be almost anywhere in the U.S. within 12 hours to set up charging stations and provide other much-needed personal cellular supplies. In 2021, we utilized this model to respond to everything from flooding in Tennessee and tornadoes in Georgia and Kentucky, to Hurricane Ida in Louisiana, and a search and rescue in Washington. $2.9M worth of in-kind products and services for disaster relief efforts provided To enhance safety protocols for our employees, we established a virtual command center in 2021 in partnership with Everbridge. This allows us to quickly identify employees and buildings in areas impacted by disasters and connect with them quickly through a mass identification tool. In addition to these initiatives, we are improving our network resiliency by implementing a multi-year network hardening plan, making sure our network is ready for all types of emergencies and natural disasters. We’re investing in constant testing and improvements to our network’s backup and response systems including thousands of generators, advanced relief and recovery tools, and coordination and mobilization plans for supporting customers and their communities in critical times. Our Network Operations Centers (NOCs) run 24/7 during natural disasters, allowing our experienced technicians and engineers to monitor our network traffic demands and weather impacts in real time. Disasters all have the same backbone. They just have different arms and different feet. A wildfire is slightly different than a hurricane, which is different than civil unrest, which is completely different than COVID or an earthquake or volcanic eruption. The one constant is the help needed.” Becky Romero Senior Manager, Business Continuity, T-Mobile 2021 CORPORATE RESPONSIBILITY REPORT 50

OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT Forecasting with StormGeo Accurately tracking a storm’s path and severity is critical for our Emergency Management Team to be ready to respond and assist with recovery efforts and restore connectivity to our customers. To help us respond quickly, we work with StormGeo, a pioneering weather forecasting operation that helps us stay ahead of the weather, identify regions under threat, and pinpoint, down to the tower and switch level, the assets that could be impacted by wind, flood, or wildfire. This gives us crucial time to prepare for situations like power outages and roll in alternative sources of electricity. Inside one of our Mobile Command Centers Disaster Relief Continued In the Eye of Ida Hurricane Ida was one of the strongest and costliest hurricanes to hit Louisiana since Hurricane Katrina. 150 mph winds battered the southern state, leaving more than a million without power. A few days later, the remnants of the hurricane caused severe flooding in the Northeast U.S. as well. Federal emergencies were declared in Louisiana, Mississippi, New York, New Jersey, and Pennsylvania. Thanks to early warning systems and our partnership with StormGeo, we were prepared and had closed over 150 stores in affected areas before Ida made landfall. Only three stores sustained damage. Seeing Our Employees through Tough Times For countless people, including T-Mobile employees, Ida threw life into turmoil. Our first move, as with any emergency, was to account for our people through Everbridge. Once everyone was deemed safe, we quickly got to work identifying on-the-ground needs. T-Mobile offers an Individual Emergency Assistance program for our employees that provides financial help to see people through tough times. Following Ida, 77 individual emergency relief funds were approved, dispensing $115,000 in financial assistance to help impacted employees cover costs ranging from home damage to basic needs such as food, clothes, and shelter. Helping Residents in Trouble Residents gathered in recreation centers, schools, and churches. Our community support team, including volunteers, was there to help them, giving out over 5,000 pre-activated phones, chargers, and cables so they could keep connected, call for further assistance, and communicate with loved ones. A total of $1.3 million in supplies was handed out in 28 locations throughout Lafayette, Baton Rouge, New Orleans, and surrounding parishes. And when the Mayor of New Orleans contacted us about helping the community get relief from the heat, we helped support four cooling centers at her request. Team Magenta went above and beyond the call of duty to do what we could to help people in the aftermath of one of the state’s worst disasters. 2021 CORPORATE RESPONSIBILITY REPORT 51

2021 CORPORATE RESPONSIBILITY REPORT OUR COMPANY OUR GO VERNANCE OUR PEO PLE OUR COM MUNITIES T T H H E E E E NVI N VI RO RO N N M M E E N NT T THE NUMBERS AN D SMALL PRINT 52 THRIVING PLANET THRIVING PLANET THRIVING PLANET THRIVING PLANET THRIVING PLANET THRIVING PLANET THRIVING PLANET THRIVING PLANET THRIVING PLANET THRIVING PLANET THRIVING PLANET THRIVING PLANET THRIVING PLANET THRIVING PLANET THRIVING PLANET THRIVING PLANET THRIVING PLANET THRIVING PLANET THE ENVIRONMENT THRIVING PLANET

OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT The Environment Ensuring connectivity for more than 100 million people requires a substantial investment in infrastructure, real estate, and our supply chain―all of which can have an impact on the environment. That’s why T-Mobile is taking ambitious steps to operate more sustainably to create a more sustainable future for everyone. We’re proud to be making real, measurable progress, including being the first in the U.S. wireless industry to be powered with 100% renewable electricity. We also achieved our science-based targets (SBTs) four years ahead of schedule, and we’re working to reduce waste and responsibly manage the lifecycle of our products. By mobilizing our resources, people, and partnerships, we can be an unstoppable force for good for the planet. 2021 Highlights 11.6M customer devices reused, resold or recycled A- on the CDP Climate Change assessment Achieved SBT: 97% reduction in combined absolute scope 1 & 2 GHG emissions from 2016 levels Achieved SBT: 16% reduction in scope 3 emissions per customer from 2016 levels energy reduction of 14%+ (MWh) per PB of data from 2019 levels $1.6 M donated to The Nature Conservancy since 2018 78% of our new wireless handset models certified through UL ECOLOGO® and EPEAT 2021 CORPORATE RESPONSIBILITY REPORT 53 100% of our electricity is sourced from renewable energy viii viii T-Mobile matches its own annual electrical usage with renewable energy from a portfolio of sources including: virtual power purchase agreements, a green direct program, renewable retail agreements, and unbundled REC purchases.

OUR COMPANY OUR GOVERNANCE OUR PE OPLE OUR C OMMUNITIES THE E NVIRONMENT THE NUMBERS A ND SMALL PRINT Feature Story: Climate Change WE DREAM BIG AND DELIVER FOR THE PLANET In early 2018, we set our sights on an ambitious renewable energy goal to reduce our carbon footprint. We went ALL IN by joining RE100, a global corporate renewable energy initiative, and setting out to source ALL of our electricity from renewable energy by 2021. And we didn’t stop there. We pushed ourselves to be just as intentional about setting ambitious carbon reduction targets. That meant setting targets backed by science and approved by the leading, global body in this space, the Science Based Targets initiative (SBTi). aimed to reduce scope 3 GHG emissions by 15% per customer by 2025 . ix We’re proud to have achieved our science-based targets four years ahead of schedule AND met our goal to source 100% of our purchased electricity from clean, renewable energy. TA RG E T Reduce combined absolute scope 1 and 2 GHG emissions by 95% by 2025 from a 2016 baseline. PROGRESS 100% By the end of 2021, combined absolute scope 1 and 2 GHG emissions decreased by 97.1% since 2016. TA RG E T Reduce scope 3 GHG emissions b y 15% per customer by 2025 from a 2016 baseline. PROGRESS 100% B y the end of 2021, scope 3 GHG emissions intensity decreased by 16.3% per customer since 2016. The C arbon Jou rney A head These a chievements de monstrate ou r c ommitment a nd drive to lead our industry by example. And we’re not stopping. The science is clear: only through relentless pursuit of progress can we put the planet on the right path to prevent the most catastrophic impacts of climate change. As a bigger and better company with even bigger and bolder aspirations, we have the size, scale, and reach to make courageous changes and inspire collective climate action. The journey is full of opportunities for us to be a catalyst for change and to drive s ustainability a cross ou r t ransformational 5 G wireless network, our buildings and retail stores, and across our entire value chain in ways that have a positive impact on our customers, employees, and the planet. When it comes to playing our part in securing a thriving, sustainable world, T-Mobile is ALL IN. i x Using a 2016 baseline. 2021 CORPORATE RESPONSIBILITY REPORT 54 In 2019, we became the first U.S. wireless provider to have two science-based targets vetted and approved by the SBTi and aligned to the 1.5°C ambition. The first addressed our operational footprint and aimed to reduce our combined absolute scope 1 and 2 GHG emissions by 95% by 2025 ix . The second addressed emissions beyond our operations across the rest of our value chain and TA RG E T Source 100% renewable electricity b y 2 021. PROG RESS 100% By the end of 2021, we sourced 100% of our electricity from renewable energ y x . x T-Mobile matches its own annual electrical usage with renewable energy from a portfolio of sources including: virtual power purchase agreements, a green direct program, renewable retail agreements, and unbundled REC purchases.

OUR COMPANY OUR G OVERNANCE OUR PE OPLE OUR C OMMUNITIES THE E NVIRONMENT THE NUMBERS A ND SMALL PRINT Staying Relentless in Our Focus on Climate Action We’re facing the challenge of a generation. Thankfully, we all have an opportunity to make meaningful changes to the ways we live, work, and connect to better contribute to a more sustainable future. It will take collaborative, coordinated action, as well as investment from many parties at local and global levels, to combat climate change, and we are committed to doing our part. By making significant and sustained cuts to GHG emissions and strengthening our climate resilience, we are helping protect the planet we all share. Earned an A- We scored at the Leadership Level for our 2021 CDP Climate Change Response Scope 1 and 2 Emissions Our science-based target for combined scope 1 and 2 G HG emissions addresses the emissions generated from our operations. The vast majority of our operational emissions—a little over 97% in 2021—comes from the purchased electricity used to power our offices, retail stores, data centers, and our nationwide network. As of December 2021, we sourced 100% of our p urchased electricity from renewable energy, enabling us to eliminate all of our scope 2 GHG emissions. To learn more about the wind and solar projects that helped us achieve this goal, check out the Energy Ma nagement section. In tandem, we’re also working to reduce our scope 1 r eliance on fossil fuels by investing in sustainable solutions across a variety of projects, including reducing reliance on diesel in data centers, implementing air-cooling enhancements and energy efficiency measures at cell towers, and investing in electric vehicles and alternative network backup power sources like batteries. Scope 3 Emissions We are taking responsibility for our full carbon footprint b y engaging stakeholders across our value chain to identify emissions hotspots and implement sustainability initiatives. To help us get a full view of scope 3 GHG emissions, we measure and report on 10 categories that are relevant to our business. We firmly believe that businesses must account for their entire footprint to drive the change needed to support a 1.5°C future. Climate Change Continued One area where we’ve collaborated to build more efficiencies is within our transportation distribution network. For example, through a recent shipping logistics optimization project we reduced the number of truck and van trips needed to deliver equipment and backup generators to our sites. Strategically grouping deliveries so that vehicles hit the road fully loaded has taken 1,146 trucks off our streets and highways, saving nearly $3 million in capital expenditure, and reducing scope 3 GHG emissions by 2,241 metric tons in 2021. 2021 CORPORATE RESPONSIBILITY REPORT 55 Our 2021 Emissions Profile 7. 3 3 M metric tons (MT) CO 2 e* Scope 1: 70,350 MT CO 2 e Scope 2: (location-based ** ): 2,893,728 MT CO 2 e Scope 2: (market-based *** ): 0 MT CO 2 e Scope 3: 7,263,741 MT CO 2 e Scope 1: Direct emissions generated from T -Mobile facilities including offices, retail stores, data centers, customer experience centers, and network operations. Scope 2: Indirect emissions from purchased e lectricity required to power all T-Mobile facilities. Scope 3: Indirect emissions generated from u pstream and downstream activities, including the products T-Mobile sells and the services it uses, including corporate travel. * Total carbon footprint uses scope 2 market-based emissions. CO 2 e is a measure used to compare the emissions from various greenhouse gases based upon their global warming potential ( OECD Glossary of Statistical T erms—Carbon dioxide equivalent definition ). C alculations are based on the GHG Protocol methodology and the EPA M andatory Greenhouse Gas Reporting Rule. Baseline year is 2016. ** T he location-based method reflects the average emissions intensity of g rids on which energy consumption occurs. *** T he market-based method reflects emissions from electricity that c ompanies have purposefully chosen.

OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT Energy Management The Power of Sustainable Energy Management Tracking, managing, and optimizing our energy use is foundational to T-Mobile’s energy management strategy. Our first priority is to reduce energy consumption by leveraging innovative technologies that drive energy efficiencies and savings across our company. Then, we work to source the energy we do use as sustainably as we can by drawing from renewable energy projects across the country. CLEAN ENERGY, DIVERSE ENERGY T-Mobile is driving change in the clean energy sector with our foundational support of the Diversity in Clean Energy (DiCE) coalition. The mission of DiCE is to grow an inclusive ecosystem that provides access to equitable opportunities for direct and indirect clean energy suppliers. Through this work, we can help support a just transition from fossil fuels to renewables. Creating Efficiencies Across Our Network As data consumption around the world continues to grow, we aim to sustain our growth and pace of our 5G network expansion without a corresponding escalation in electricity use. Because the majority of our energy consumption comes from powering our network, network-related efficiencies have a massive impact on our overall energy footprint. We set a bold goal of reducing our energy consumption by 95% per petabyte of data traffic by 2030, from a 2019 baseline. That means we will, across our business, use 20 times less total energy each time a customer views a webpage or streams a song, compared to 2019. We’re making progress—and we won’t stop until we get there. OUR ENERGY EFFICIENCY TARGET Achieve a 95% reduction in energy consumption (M Wh) per petabyte (PB) of data traffic by 2030, from a 2019 baseline. PROGRESS TOWARD ACHIEVEMENT 15.2% We achieved a 14.4% reduction in energy consumption (MWh) per petabyte (PB) of data traffic between 2019 and the end of 2021, using 349 MWh of energy per PB of data traffic on our network in 2021. In 2021, we continued to realize network synergies from the merger, strategically decommissioning thousands of targeted cell sites that were deemed redundant, which resulted in an estimated savings of approximately 500,000 MWh. We also turned on features across approximately half our network sites that enabled our radio-network equipment to optimize energy consumption and drive further efficiencies. This is in addition to the cooling enhancements we’ve made at select cell sites by replacing air conditioning units with direct air-cooling fans to more efficiently control the on-site temperature of cell towers. Recognized by the Environment+Energy Leader Awards for our energy management efforts #3 on the National Top 100 List of the EPA Green Power Partnership’s Top Partner rankings BUILDINGS THAT RUN ON LESS Energy smart offices: T-Mobile has installed energy-efficient infrastructure and LED lighting with motion sensors across millions of square feet of renovated office spaces. To further optimize efficiency, we installed energy management systems across thousands of retail locations. The new systems include enhanced power monitoring and smart thermostats that allow us to build schedules that make our HVAC units more efficient, without affecting customer or employee comfort. Plus, they allow our teams to diagnose and fix HVAC issues remotely and see which units may be running inefficiently so we can proactively replace them before they fail. Combined with our LED lighting and lighting controls upgrades at hundreds of stores, we’re able to save approximately 45,000 MWh annually. We’re also continuing to further improve energy efficiency at our data centers. We’re implementing controls and systems that allow us to analyze even more granular data on power usage and make data-driven decisions on how to make our facilities more efficient. In corporate offices, we’re exploring equipping heavily trafficked spaces with motion sensors to drive smarter energy savings today and for years to come. 2021 CORPORATE RESPONSIBILITY REPORT 56

OUR COMPANY OUR G OVERNANCE OUR PE OPLE OUR C OMMUNITIES THE E NVIRONMENT THE NUMBERS A ND SMALL PRINT 100% Renewable Electricity. Check. Our energy reduction and efficiency measures are c omplemented by our commitment to source 100% of our electricity from renewable energy, a goal we achieved in 2021 despite our historic merger that significantly expanded our electricity needs. By using electricity generated from the wind and sun, w e are powering our operations with clean energy sources that will never run out and do not release harmful GHGs into the atmosphere as they generate electricity. To help reach our goal we invested in nine large-scale w ind and solar farm projects across the country that are contracted to provide us with approximately 3.4 million MWh of renewable energy per year. These investments are a shining example of how we use our purchasing power for good, driving demand for clean energy and bringing more renewable energy to more local grids across the nation. As of 2021, our renewable energy portfolio included e ight virtual Power Purchase Agreements (PPAs), one Green Direct program, 19 retail agreements, community solar projects, and unbundled Renewable Energy Certificates that support projects across the country―that’s enough wind and solar power annually to account for every unit of electricity we consumed! Moving forward, we plan to invest in and add more renewable energy projects to our portfolio to match our electricity needs. Community Solar Across the Country We’re ramping up investments in community solar projects across the country. These projects help generate clean energy flowing to local electric grids, which reduces the use of fossil fuels and lowers emissions in the community. When T-Mobile subscribes to community solar projects, we benefit by receiving renewable energy credits that reduce our electricity cost each month, while supporting the renewable energy entering the grid—a win for the business, for clean energy, and the communities it serves. In 2021, we signed 37 community solar projects w hich represent greening local energy grids with more than 2.1 million MWh over 25 years in Maine, Massachusetts, Minnesota, New York, Colorado, and Oregon. IN CONVERSATION WITH SAM KIMMINS, DIRECTOR OF ENERGY, CLIMATE GROUP RE100 is a global initiative bringing together the w orld’s most influential businesses committed to 100% renewable electricity. Led by Climate Group, i n partnership with CDP , its mission is to drive change t oward 100% renewable grids, both through the direct investments of its members, like T-Mobile, and by working with policymakers to accelerate the transition to a clean economy. Q. Why is it so important for the telecommunications i ndustry to be a part of the renewable energy conversation? The telco industry has a crucial role to play in this transition owing to the vast amounts of electricity consumed through its day-to-day operations. As critical national infrastructure suppliers, telco businesses have a substantial and authoritative voice when it comes to communicating the need to do more to update our energy markets and supply infrastructure to facilitate investment in cheap, clean renewables. Q. How significant is this type of achievement when it comes to global efforts to combat climate change? The value of a public commitment from companies such as T-Mobile cannot be understated. It enables T-Mobile, and companies like it, to add their weight to the overall membership advocating for change. The electricity consumption of RE100 members is now greater than that of the U.K., at over 380+ TWh per year, meaning that when our members all achieve their RE100 goals, that’s the equivalent of a country going 100% renewables. This is not only good for the planet; the increasing scale of corporate renewables investment is rapidly bringing down renewable energy costs for the benefit of all. Q. Apart from reducing energy consumption through efficiency measures and maintaining the RE100 commitment going forward, what more can companies do to show leadership in transforming the renewable energy sector? There are two major areas that businesses can focus on beyond their own commitments. Firstly, corporations can advocate for better access to renewable energy. Making the case for a level playing field by guaranteeing your purchase of renewables should they become available is a big contributor to helping a country gain access to more renewables while bringing down costs. Secondly, it’s looking beyond your scope 1 and 2 GHG emissions to those in your supply chain―scope 3 GHG emissions. While the RE100 commitment only covers those emissions directly produced by a company, many members are going above and beyond by looking at those indirect emissions. Q. What do rising energy costs mean for RE100 m embers looking to source a reliable supply of electricity at a stable cost? By making the switch to renewables, companies are helping to mitigate the potential for future price fluctuations in the long term and ideally delivering business savings. Energy Management Continued 2021 CORPORATE RESPONSIBILITY REPORT 57

OUR COMPANY OUR GOVERNANCE OUR PEOPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT Waste and Recycling Taking on Waste in Every Form Waste comes in many forms—from everyday items like used paper cups and batteries, to a wide range of electronic and network infrastructure equipment. We know that our customers and employees care about the waste that is generated by the products and services they purchase and the companies they buy from. Across our business we look for effective ways to minimize the waste we produce and responsibly dispose of the waste we generate. Our approach includes assessing our operations to understand waste reduction opportunities, removing barriers to make it easier for employees to responsibly dispose of items, and prioritizing repair, reuse, and recycling whenever possible. We’ll be the first to admit that our waste reduction and recycling efforts are a work in progress and often depend on the infrastructure and commitment in our local municipalities, but we are applying the same relentless mindset to this challenge as to other pain points our industry might face. Inspiring Wise Decisions on Waste Each one of us makes daily decisions about the items we toss in the trash. Often, the decision to send something to landfill or recycle it comes down to access and information. To help address this, we offer as many opportunities as possible for our employees to have access to responsible disposal options and the information needed to make informed decisions. For example, every corporate retail store across the country has a collection center that provides employees with an easy way to appropriately dispose of everything from batteries and lamps to aerosol cans and small electronics. We also launched the Magenta Ambassador program in our Bellevue, WA; Overland Park, KS; Frisco, TX; and New York, NY offices, which provides an in-person point of contact who can be a champion for improving the employee experience at those locations. Part of the ambassadors’ role is raising awareness of the local programs and resources available, including waste disposal, recycling, and composting options. Waste systems and needs vary by location, and we want to empower our employees to make informed decisions no matter where they are working. Network E-Waste is a Valuable Resource Responsibly managing electronic waste, or e-waste, is one of the biggest opportunities in our industry and an area where we can have a massive impact on the environment. Every piece of equipment that keeps us connected—whether through our transformational 5G network or the latest wireless device—contains precious metals, glass, and other raw materials. Recognizing that resources are not limitless, our goal is to recover electronic equipment and products throughout our value chain and maximize their useful life by repairing and redeploying them. As we continue to strategically decommission redundant cell sites, we first assess network equipment to see what can be repaired and reused elsewhere across our business. This not only prolongs the life of the equipment, but it also saves costs and resources. Equipment that isn’t used by T-Mobile is either responsibly recycled through R2-certified and e-steward companies or resold to vendors with the intention of being reused. In 2021, we recycled 90% of the materials we didn’t reuse internally with the remaining 10% resold to vendors for reuse. The more resources that can be reclaimed from e-waste, the less that need to be extracted from the earth. Shaping the Circular Economy Together We recognize the importance of reducing the amount of e-waste associated with devices. It’s why the concept of the circular economy is so critical for our industry —it works to maximize the product lifecycle and minimize waste at the same time. By partnering with others through the Global Enabling Sustainability Initiative (GeSI) and the Global System for Mobile Communications Association (GSMA), we can shape circular economy strategies for the telecommunications industry and make meaningful recommendations to device manufacturers. We are also actively participating in the Retail Industry Leaders Association (RILA) waste diversion sub-committee, which focuses on best practices for recycling and reusing devices across the retail sector. 2021 CORPORATE RESPONSIBILITY REPORT 58

OUR COMPANY OUR GOVERNANCE OUR PE OPLE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT Product Lifecycle Management Extending the Life of Every Device E-waste has become a critical global issue. 53 million metric tons of electronic waste were discarded worldwide in 2019 alone . Making more sustainable choices when it comes to the lifecycle of electronic devices is important for several reasons: xi ■ Left to decompose in landfill, electronic devices can leach hazardous compounds such as lead or cadmium into the groundwater. ■ Discarded devices may be suitable for refurbishment and subsequent use by someone else. ■ Broken devices are rich in precious metals and recyclable materials that can be used in manufacturing new items versus extraction from the ground via highly carbon-intensive mining. As a wireless provider, we can play an important role in keeping devices out of landfills by providing our customers with ways to extend the lifecycle of their de vices when possible. Each year, millions of devices come back to T-Mobile through our Device Reuse and Recycling program, and our reverse logistics partners have continued to enhance the sorting and assessment process by leveraging new technology. More recently, our partners have used a robotic solution that takes devices through an automated machine- based evaluation to check the cosmetic quality and functionality of each device and determine whether it can be resold and reused or recycled. With the help of these machines, we’re able to evaluate devices more rapidly and objectively, improving the efficiency of the overall process and extending the device lifecycle for millions of smartphones, tablets, smartwatches, and more. For devices that can’t be reused, we work with recycling par tners that are certified to the rigorous and industry- leading R2 standard, which provides a common set of processes, safety measures, and documentation requirements for electronics recyclers. T-Mobile is the only U.S. wireless carrier to participate in t he Environmental Protection Agency’s (EPA) Sustainable Materials Management Electronics Challenge. This program challenges major manufacturers and retailers of electronics to send 100% of the e-waste they collect to third-party certified recyclers, increase e-waste collections, and publish data on recovery and disposal. We received the Gold Tier Award for our 2021 Device Reuse and Recycling program—the third straight year we were recognized with this honor. Tr a d e i n Customers can swap an eligible device for credit toward a new one, with the old device automatically entering our Device Reuse and Recycling program. It’s a win-win. Customers can find out what a device is worth with our trade-in estimator tool and get a new device. We either find a new home for the unwanted devices or ensure that the recyclable components and materials are put to good use. Recycle in store T-Mobile accepts smartphones, tablets, smartwatches, hotspots, or IoT items at our stores to be upcycled or recycled for free. We provide clear instructions for customers on how to clear their phones of personal data so they’re ready for recycling. 11.6M devices were reused, resold, or recycled through our Device Reuse and Recycling program in 2021 x i The Conversation. 20 22. Consume r electronics ha ve cha nged a l ot in 20 years — systems for managing e-waste aren’t keeping up. 2021 CORPORATE RESPONSIBILITY REPORT 59

OUR COMPANY OUR G OVERNANCE OUR PE OPLE OUR C OMMUNITIES THE E NVIRONMENT THE NUMBERS A ND SMALL PRINT Design for the Environment We know many of our customers care about making sustainable purchasing choices. We encourage our device suppliers to participate in the UL ECOLOGO Certification Program, a voluntary independent certification that covers materials use, energy consumption, repairability, end-of- life management, packaging, and more. Approximately 78% of our new wireless handset models were certified through UL ECOLOGO and EPEAT Certifications in 2021. Going forward, T-Mobile will extend the range of wireless devices that undergo ECOLOGO or equivalent certification to include tablets and wearables. 78% of our new wireless handset models certified through UL ECOLOGO and EPEAT T-Mobile is on the ECOLOGO Standard Technical Panel for UL 110 (the Standard for Sustainability for Mobile Phones) and was involved in developing the industry’s first-ever environmental standard for wireless devices. Collaborating for Progress in Sustainable Packaging Sustaina ble packaging is one way we show our love for our customers and our planet at the same time. We strive to reduce packaging waste that goes to landfill and not saddle our customers with plastic trays and inserts they cannot recycle. We are working to evolve our device and accessory pa ckaging and shipping materials to be sourced from more sustainable, recyclable materials. In coordination with CTIA, we developed sustainable pa ckaging guidelines that help minimize the impact and footprint of packaging. The guidelines encourage suppliers to: ■ Create packaging that has as little single-use plastic as possible ■ Avoid any constructions that prevent recycling, like metal wire ties ■ Clearly label packaging so consumers know their recycling options ■ Use paper fibers from reputable, certified sources ■ Consider alternative, less environmentally harmful printing processes, such as using water-or soy-based inks Pivet, the case brand with its proprietary Self-Cycle TM technology, was among the new sustainable products we introduced to our accessories portfolio in 2021. It’s a case option that delivers premium design and functionality while being 100% bioavailable to nature’s “decay agents” found in locations like landfills. Pivet is an example of new materials technology opening up more sustainable choices for customers. Product Lifecycle Management Continued 2021 CORPORATE RESPONSIBILITY REPORT 60

Natural Resources Management Using Natural Resources Responsibly T-Mobile is committed to being a responsible steward of the natural resources we use. Our Environmental Policy lays out our commitments to do our part to protect the planet we all share. We strive to conserve water use throughout our operations, follow responsible paper management practices and sustainable packaging guidelines, and increase the purchase of products designed and manufactured in an environmentally sustainable way. Plus, we take a highly collaborative approach to natural resource management and conservation efforts, working closely with suppliers and non-profits, as well as in alliance with other corporations, to ensure we are improving efficiencies and following best practices across our value chain. Supporting Suppliers Who Use Less T-Mobile’s Responsible Sourcing Guidelines help us select and support the suppliers who source materials the right way. Our suppliers are an important part of our business, and these guidelines outline our expectations and ensure everyone is aligned to the same responsible sourcing practices, including: ■ Maximizing their use of recycled fibers and using natural fiber efficiently ■ Minimizing use of paper-based records in their own operations ■ Following sustainable forest management practices including obtaining certifications from independent bodies like the Forest Stewardship Council wherever a particular risk of deforestation is identified ■ Respecting indigenous and local land rights ■ Demonstrating best practice in mill and printer performance ■ Showing improvements in water and energy efficiency ■ Not using conflict minerals For a detailed look, check out our full Responsible Sourcing Guidelines . Water We strive to conserve water across our operations and understand the key role it plays in global supply chains. As part of the Science Based Target Network (SBTN) Corporate Engagement Program, we collaborate with other organizations on developing methods and tools to set science- based targets for nature, including water use targets. Wood fiber Responsible wood fiber usage protects forests, so we work to manage the use of paper and paperboard packaging material across our operations. For example: Paperless billing for all customers unless they expressly ask for paper bills ■ Our Responsible Sourcing Guidelines ensure suppliers follow best practices in regard to forest stewardship, recycling, and indigenous land rights ■ Minerals We are concerned about the human rights abuses and risks associated with the extraction, transport, and trade of certain minerals in the Democratic Republic of the Congo (DRC) and adjoining countries. These trade minerals, referred to as “conflict minerals,” include columbite- tantalite (coltan), cassiterite, gold, wolframite, and their derivatives. Our Responsible Sourcing Guidelines outline our expectations that suppliers do not use conflict minerals, as well as guiding them where necessary in improving due diligence. 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE NUMBERS AND SMALL PRINT 61 OUR COMPANY THE ENVIRONMENT

Natural Resources Management Continued Partnering to Protect the Planet Truly protecting the planet will require looking beyond our own operations to areas where we can meaningfully partner with others. For the last few years, T-Mobile has joined forces with The Nature Conservancy (TNC) to mobilize our resources and our customers around Earth Day and bolster global conservation efforts. Since 2018, we’ve donated $1.6 million to TNC programs that work to establish environmentally conscious practices to prevent habitat loss and promote biodiversity on a large scale. Through our annual campaigns, we’ve engaged customers through the T-Mobile Tuesdays app to help direct our funding to programs, such as: • Plant a Billion Trees —a major forest restoration program aimed at slowing climate change and biodiversity loss • The Family Forest Carbon Program —a project aimed at helping family and small landowners across the U.S. gain access to resources and capital to improve the health of their forests and fight climate change • Living with Fire —a program to develop and implement fire mitigation strategies that reduce wildfire risks and restore health and diversity to natural lands ENVIRONMENTAL GOVERNANCE To help drive sustainability outcomes across the business, the T-Mobile Sustainability Steering Committee meets quarterly to discuss priority environmental sustainability topics and initiatives. Comprised of executive leaders from cross- functional groups, the committee works to drive a holistic, enterprise-wide discussion and to align sustainability efforts at T-Mobile, as well as ensuring functional visibility, accountability, and engagement in the development of company-wide plans. The committee is co-led by our Executive Vice President and Chief Communications Officer and our Executive Vice President, Corporate Development and Strategy. Key initiatives overseen by the committee are communicated through ESG updates to the Nominating and Corporate Governance Committee. 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE NUMBERS AND SMALL PRINT 62 OUR COMPANY THE ENVIRONMENT

THE NUMBERS AND SMALL PRINT THE ENVIRONMENT OUR GOVERNANCE OUR COMMUNITIES OUR PEOPLE 2021 CORPORATE RESPONSIBILITY REPORT 63 OUR COMPANY THE NUMBERS AND SMALL PRINT

The Numbers and Small Print Honest and straightforward communications, backed by credible data, is what we’re about. This report covers the domestic operations and activities of T-Mobile US, Inc. for the calendar year 2021 (January 1 to December 31), unless otherwise stated. It has been prepared in accordance with the Global Reporting Initiative (GRI) Standards: Core option. It is also aligned to the disclosure requirements of the Sustainability Accounting Standards Board (SASB) Standards for our industry. Information Integrity T-Mobile management is responsible for the preparation and integrity of the information reported for calendar year 2021. Through a system of internal controls, including a comprehensive verification process involving internal subject matter experts, we believe this information accurately represents our domestic responsibility activities and performance results for the calendar year. We continued to improve our data collection process by utilizing a centralized ESG collection tool which allows the internal subject matter experts to collaborate, collect data, and streamline our extensive review and approval process. External verification over specified GHG and energy metrics is provided by Apex Companies, LLC. THE ENVIRONMENT OUR GOVERNANCE OUR COMMUNITIES OUR PEOPLE 2021 CORPORATE RESPONSIBILITY REPORT 64 OUR COMPANY THE NUMBERS AND SMALL PRINT

GRI Index Notes About This Report This report contains certain forward-looking statements based on T-Mobile management’s current assumptions and expectations, including statements regarding our ESG targets, goals, commitments and programs and other business plans, initiatives, and objectives. These statements are typically accompanied by the words “aim,” “hope,” “believe,” “estimate,” “plan,” “aspire,” “may,” “could,” “will,” or similar words. All such statements are intended to enjoy the protection of the safe harbor for forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended. Our actual future results, including the achievement of our targets, goals, or commitments, could differ materially, and adversely, from our projected results as the result of changes in circumstances, assumptions not being realized, or other risks, uncertainties, and factors. Such risks, uncertainties, and factors include the risk factors discussed in Item 1A of our most recent Annual Report on Form 10-K and subsequent quarterly reports on Form 10-Q filed with the Securities and Exchange Commission (SEC) (such documents are also available on our investor page), as well as, with respect to our ESG targets, goals and commitments outlined in this reporting or elsewhere, and the challenges, assumptions and other methodological considerations associated with same. As such, readers should not place undue reliance on such forward-looking statements. We urge you to consider all of the risks, uncertainties, and factors identified above or discussed in such reports carefully in evaluating the forward-looking statements in this report. T-Mobile cannot assure you that the results reflected or implied by any forward-looking statement will be realized or, even if substantially realized, that those results will have the forecasted or expected consequences and effects. The forward-looking statements in our reporting are made as of the date in which this report is published and we undertake no obligation and expressly disclaim any duty to update these forward-looking statements to reflect subsequent events or circumstances. Additionally, this report contains ESG-related statements based on hypothetical scenarios and assumptions as well as estimates that are subject to a high level of inherent uncertainty, and these statements should not necessarily be viewed as being representative of current or actual risk or performance, or forecasts of expected risk or performance. In addition, historical, current, and forward-looking environmental and social-related statements may be based on standards and metrics for measuring progress, as well as standards for the preparation of any underlying data for those metrics, that are still developing and internal controls and processes that continue to evolve; while these are based on expectations and assumptions believed to be reasonable at the time of preparation, they should not be considered guarantees. Moreover, our disclosures based on any standards may change due to revisions in framework requirements, availability of information, changes in our business or applicable governmental policies, or other factors, some of which may be beyond our control. THE ENVIRONMENT OUR GOVERNANCE OUR COMMUNITIES OUR PEOPLE 2021 CORPORATE RESPONSIBILITY REPORT 65 OUR COMPANY THE NUMBERS AND SMALL PRINT The events, scenarios, and efforts discussed in this report, including both forward-looking statements and other statements, may be significant; however, the inclusion of such statements is not an indication that these contents are necessarily material for the purposes of complying with or reporting pursuant to the U.S. federal securities laws and regulations, even if we use the word “material” or “materiality” in this document in relation to those statements or in other materials that we may release from time to time in connection with the matters discussed herein. Moreover, given the uncertainties, estimates, and assumptions required to make some of the disclosures in this report, and the timelines involved, materiality is inherently difficult to assess far in advance. In addition, given the inherent uncertainty of the estimates, assumptions, and timelines contained in this report, we may not be able to anticipate in advance whether or the degree to which we will or will not be able to meet our plans, targets, or goals. Website references throughout this document are provided for convenience only, and the content on the referenced websites is not incorporated by reference into this document.

ESG Data 2021 ESG Data 2021 RESPONSIBLE BUSINESS Corporate Governance Independent Directors (#) 5 2020 5 2021 Independent members of the Audit Committee (%) 100 2020 100 2021 Independent members of the Nominating and Corporate Governance Committee (%) 67 2020 67 2021 Independent members of the Compensation Committee (%) 20 2020 20 2021 Women on the Board of Directors (%) 14.0 2020 28.6 2021 Percentage of Directors who are members of traditionally underrepresented racial/ ethnic groups (%) 21.0 2020 28.6 2021 Size of the Board of Directors (#) 14 2020 14 2021 Responsible Supply Chain Diverse supplier spend ($ billions) 3.00 2020 3.27 2021 Suppliers (by sourceable spend) assessed on their environmental and social performance through the EcoVadis tool (%) 30 2020 38 2021 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT 66 OUR COMPANY

SOCIAL — OUR PEOPLE DE&I T-Mobile employees who self-identify as veterans (#) 3,432 2020 3,26 0 2021 T-Mobile employees who self-identify as individuals with disabilities (#) 3,294 2020 4,28 3 2021 T-Mobile employees who self-identify as LGBTQ+ (#) 1,621 2020 2,292 2021 T-Mobile Total U.S. workforce who are people of color (%) 6 0.1 2020 5 9. 5 2021 T-Mobile Total U.S. workforce: people manager who are people of color (%) 5 0.1 2020 49. 6 2021 T-Mobile Total U.S. workforce: executives (Dir+) who are people of color (%) 23.5 24.5 2020 2021 T-Mobile Total U.S. workforce who are women (%) 40.6 2020 40.9 2021 T-Mobile Total U.S. workforce who are women people managers (%) 35.8 2020 35.8 2021 T-Mobile Total U.S. workforce who are women people executives (Dir+) (%) 32.4 2020 33.8 2021 ESG Data 2021 Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PE OPLE OUR G OVERNANCE OUR C OMMUNITIES THE E NVIRONMENT THE NUMBERS A ND SMALL PRINT 67 OUR COMPANY

SOCIAL — OUR PEOPLE CONTINUED Employee Engagement, Learning, and Development Amount paid in Tuition Assistance ($ millions) 22.4 2020 20.1 8 2021 Hours employees participated in training xi (millions of hours) 3.7 2020 5.4 2021 Health, Safety, and Wellness Employees (full and part-time) eligible for health benefits on Day 1 of their employment xii (%) 100 2020 100 2021 Rate of recordable work-related injuries (per 200,000 hours worked) 0.27 2020 0.27 2021 SOCIAL — OUR COMMUNITY Philanthropy Disaster Response in-kind support ($ millions) 1.3 2020 2.9 2021 Amount donated by T-Mobile and the T-Mobile Foundation ($ millions) 16.5 2020 32.8 2021 Amount donated by T-Mobile’s employees ($ millions) 3.9 2020 3.7 2021 Employee volunteer hours (#) 48,536 2020 52,478 2021 xi The number of hours of training includes only trackable training hours completed in our formal Learning Management System by full-time and part-time employees. xii The percentage excludes interns who are classified as temporary employees. ESG Data 2021 Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PE OPLE OUR G OVERNANCE OUR C OMMUNITIES THE E NVIRONMENT THE NUMBERS A ND SMALL PRINT 68 OUR COMPANY

ENVIRONMENT Climate Change Emission intensity (MTCO₂e/PB) 471.05 2020 31 9.1 8 2021 Scope 1 emissions (MTCO₂e) 5 3 ,1 8 0 2020 70,350 2021 Scope 2 emissions (market-based) (MTCO₂e) 1,858,206 2020 0 2021 Scope 2 emissions (location-based) (MTCO₂e) 2,755,796 2020 2021 2,893,728 Scope 3 emissions (MTCO₂e) 7, 0 3 3 , 8 2 1 2020 7,263,741 2021 Total scope 1, 2, and 3 emissions (using market-based scope 2) (MTCO₂e) 8,945,207 2020 7, 3 3 4 , 0 9 1 2021 Waste and Recycling Wireless devices collected from Reuse and Recycling Program (millions) 7.9 2020 11.6 2021 Natural Resources Management Water consumption (cubic meters (m 3 )) 1,086,662 2020 1,054,583 2021 Energy Management Total energy consumption within the organization (MWh) 7,1 5 8 , 7 76 2020 8,028,396 2021 Energy intensity (MWh/PB) 471.05 2020 3 49. 3 9 2021 Percentage of energy from grid electricity (%) 96.90 9 7. 2 0 2020 2021 Percentage of energy supplied from renewable energy (%) 2020 9 7. 2 0 2021 24.40 ESG Data 2021 Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT 69 OUR COMPANY

T-Mobile Material Topic Definitions Material Topic Definition Business continuity and network resilience Managing risks and creating systems of prevention and recovery to deal with potential threats to a company, i.e. disaster response efforts, geopolitical events, building network resilience, and mitigating risks that could interrupt network service. Corporate governance Structures in charge of managing, overseeing, and directing a company and integrating ESG across the business. Digital equity Equal access and opportunity to connectivity, including affordability of services, accessibility no matter ability, income or location, and digital education to bridge digital literacy divides. Digital security and privacy Providing a secured network for a safe and secure online experience, including the protection of personal information and consumer data. Employee attraction, development, and engagement Attracting, retaining, and developing the best talent through education, learning, training, and fair recruitment and compensation practices. Ethical business practices The fair, transparent, and moral code of conduct to the strategic and operational management of a business. Economic contribution Making a positive contribution to national and local economies. For instance, through jobs created, taxes paid, economic value added. Employee diversity (equity and inclusion) Diversity of our workforce and equal opportunity for employees of different backgrounds. Energy management Using energy more efficiently and opting for renewable energy sources where possible. Greenhouse gas (carbon) emissions and climate change Taking clear action to reduce our impact on the climate and reducing emissions, like carbon, generated from business activities. Developing innovative technologies that promote long-term sustainability. Human rights A commitment to respect and promote human rights and social principles in every place a company operates, including its business partners and supply chain. Material Topic Definition Health, safety, and wellness Ensuring the workers across the value chain work in safe conditions where their safety, health, and mental well-being are prioritized. Natural resources management conservation Protecting and conserving natural resources, such as water, trees, wildlife, and land. Open internet and competitive behavior Protecting and committing to open internet access where all data is treated equally with respect to content, application, and service. Philanthropy and community engagement Supporting, developing, and enhancing the well-being and livelihoods of communities. Product lifecycle management Minimizing environmental and social impacts during the product lifecycle (i.e. take-back programs, reduction of plastic and packaging). Partnerships and collaboration and cross- industry collaboration Promoting and advancing sustainability across the telecom industry through advocacy, participation in industry associations, external partnerships, and cross-industry collaboration. Responsible marketing The responsible and transparent communication, promotion, and/or selling of products to consumers. Responsible use of products and services Ensuring customers are using products and services responsibly and that their digital well-being is protected. Sustainable and responsible supply chain Transparent supply chain management and responsible supplier engagement that protects environmental, social, and governance (ESG) values. Waste and recycling Reducing the amount of waste generated across operations and responsibly disposing/recycling all waste streams. These definitions were used in our third-party materiality assessment which was intended to identify and prioritize ESG issues relevant to our business and key stakeholders. Please refer to the ESG materiality matrix in the 2020 Corporate Responsibility Report for more information. 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT 70 OUR COMPANY

GRI Index GRI Index The table below sets out our responses to relevant Global Reporting Initiative (GRI) disclosures, including select material topics identified in collaboration with stakeholders as part of our 2021 ESG materiality assessment. Disclosure# Disclosure Topic 2021 Response Organizational Profile 102-1 Name of the organization T-Mobile US, Inc. 102-2 Activities, brands, products, and services T-Mobile 2021 Form 10-K Part I pages 5-7 102-3 Location of headquarters Bellevue, Washington and Overland Park, Kansas 102-4 Location of operations T-Mobile 2021 Form 10-K Part I pages 1, 8 102-5 Ownership and legal form T-Mobile 2021 Form 10-K Part I page 1 T-Mobile common stock is traded on the NASDAQ Stock Market LLC under the symbol “TMUS.” 102-6 Markets served T-Mobile 2021 Form 10-K Part I pages 5-7 102-7 Scale of the organization T-Mobile 2021 Form 10-K Part I pages 5-8; Part II pages 27, 32 102-8 Information on employees and other workers T-Mobile 2021 Form 10-K Part I page 8 102-9 Supply chain overview Our Procurement and Supply organization spends billions of dollars on products, goods, and services annually, procuring everything our company needs to run our business, from hardware and network equipment to software, spectrum assets, and transportation. Engaging with small, medium, and large suppliers across the globe, we work to provide access and opportunities for all our suppliers and grow a robust supply chain that reflects our diversity and values. We are a company committed to conducting our business in a socially, environmentally, and economically responsible manner. This commitment extends to our supply chain partners and the goods and services they provide. Our Supplier Code of Conduct and Responsible Sourcing Guidelines outline the policies and guidelines that govern our supply chain partnerships and sustainability performance is a contributing factor to how we award contracts. In 2020, we began working with EcoVadis to better evaluate our supply chain across four key areas: environmental, labor and human rights, ethics, and sustainable procurement. We have received assessments from suppliers representing approximately 38% of our sourceable spend. 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT 71 OUR COMPANY

GRI Index Continued Disclosure# Disclosure Topic 2021 Response 102-10 Significant changes to the organization and its supply chain T-Mobile 2021 Form 10-K Part I page 5; Part II pages 28-31 102-11 Precautionary principle or approach T-Mobile 2021 Form 10-K Part III page 115 2021 Corporate Responsibility Report: Our Governance > Corporate Governance Our standard management practices considers many factors, including potential positive and negative societal impacts, when making strategic business decisions. 102-12 External initiatives CEO Action for Diversity & Inclusion Pledge; Founding Signatory Disability:IN’s CEO Letter; Supporter of the Equality Act; Signed the Human Rights Campaign’s letter against discriminatory state legislation targeting the LGBTQ+ community 102-13 Membership of associations CTIA, Global e-Sustainability Initiative (GeSI), BSR, EPA Green Power partnership, RE100 Strategy 102-14 Statement from senior decision-maker 2021 Corporate Responsibility Report: Our Company > CEO Statement 102-15 Key impacts, risks, and opportunities 2021 Corporate Responsibility Report: Our Company > CEO Statement 2021 Corporate Responsibility Report: Our Company > ESG Approach Ethics and Integrity 102-16 Values, principles, standards, and norms of behavior 2021 Corporate Responsibility Report: Our Company > Corporate Vision, Mission, and Values Code of Business Conduct Supplier Code of Conduct 102-17 Mechanisms for advice and concerns about ethics 2021 Corporate Responsibility Report: Our Governance > Ethical Business Practices T-Mobile Speak Up Policy T-Mobile Integrity Line (external reporting site) Governance 102-18 Governance structure 2021 Corporate Responsibility Report: Our Governance > Corporate Governance 2021 Corporate Responsibility Report: Our Company > ESG Approach > ESG Oversight 2022 Proxy Statement 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT 72 OUR COMPANY

GRI Index Continued Disclosure# Disclosure Topic 2021 Response Stakeholder Engagement 102-40 List of stakeholder groups 2021 Corporate Responsibility Report: Our Company > ESG Approach 102-41 Collective bargaining agreements T-Mobile is committed to recognizing employees’ rights to organize, and to refrain from organizing. We abide by both the letter and the spirit of the U.S. National Labor Relations Act (NLRA), under which employees have the right to decide whether to support or not support a union. We train our supervisors on the NLRA, which stipulates the legal requirements concerning union rights. 102-42 Identifying and selecting stakeholders 2021 Corporate Responsibility Report: Our Company > ESG Approach 102-43 Approach to stakeholder engagement 2021 Corporate Responsibility Report: Our Company > ESG Approach 102-44 Key topics and concerns raised 2021 Corporate Responsibility Report: Our Company > ESG Approach Reporting Practices 102-45 Entities included in the consolidated financial statements T-Mobile 2021 Form 10-K Part I pages 4, 28 102-46 Defining report content and topic boundaries 2021 Corporate Responsibility Report: About This Report 2021 Corporate Responsibility Report: Our Company > ESG Approach 102-47 List of material topics 2021 Corporate Responsibility Report: Our Company > ESG Approach 102-48 Restatements of information None 102-49 Changes in reporting None 102-50 Reporting period January 1, 2021 to December 31, 2021 unless otherwise stated 102-51 Date of most recent report 2021 102-52 Reporting cycle Annual 102-53 Contact point for questions regarding the report ESG.Reporting@T-Mobile.com 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT 73 OUR COMPANY

GRI Index Continued Disclosure# Disclosure Topic 2021 Response 102-54 Claims of reporting in accordance with the GRI Standards This report has been prepared in accordance with the GRI Standards: Core option. 102-55 GRI content index 2021 Corporate Responsibility Report: The Numbers and Small Print > GRI Content Index 102-56 External assurance Third-party limited assurance was provided for T-Mobile’s greenhouse gas (GHG) emissions and energy use data for calendar year 2021. See T-Mobile’s Assurance Statement on our reporting page for more information. Economic Disclosures Material Topic: Digital Equity GRI 203: Indirect economic impacts 103-1 Explanation of the material topic and its boundaries 2021 Corporate Responsibility Report: Our Company > ESG Approach 2021 Corporate Responsibility Report: The Numbers and Small Print > Material Topic Definitions 103-2 The management approach and its components 2021 Corporate Responsibility Report: Our Communities > Digital Equity 103-3 Evaluation of the management approach 2021 Corporate Responsibility Report: Our Company > ESG Approach 2021 Corporate Responsibility Report: Our Communities > Digital Equity 203-1 Infrastructure investments and services supported 2021 Corporate Responsibility Report: Our Communities > Digital Equity Environmental Disclosures Material Topic: Energy Management GRI 302: Energy management 103-1 Explanation of the material topic and its boundaries 2021 Corporate Responsibility Report: Our Company > ESG Approach 2021 Corporate Responsibility Report: The Numbers and Small Print > Material Topic Definitions 103-2 The management approach and its components Environmental Policy CDP Climate Change Response 2021 Corporate Responsibility Report: The Environment > Energy Management 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT 74 OUR COMPANY

Disclosure# Disclosure Topic 2021 Response 103-3 Evaluation of the management approach 2021 Corporate Responsibility Report: Our Company > ESG Approach 302-1 Energy consumption within the organization Total fuel consumption within the organization from non-renewable sources: 800,348 GJ ■ Fleet diesel: 4,309 GJ ■ Fleet gasoline: 422,431 GJ ■ Jet fuel: 16,572 GJ ■ Stationary diesel: 147,791 GJ ■ Propane: 20,996 GJ ■ Natural gas: 188,249 GJ Total fuel consumption within the organization from renewable sources: 0 GJ In joules, watt-hours or multiples, the total: ■ Electricity consumption: 7,806,077 MWh ■ Heating consumption: 0 MWh ■ Cooling consumption: 0 MWh ■ Steam consumption: 0 MWh In joules, watt-hours or multiples, the total: 0 MWh ■ Electricity sold: 0 MWh ■ Heating sold: 0 MWh ■ Cooling sold: 0 MWh ■ Steam sold: 0 MWh Total energy consumption within the organization, in joules or multiples: 28,902,225 GJ: ■ Fleet diesel: 4,309 GJ ■ Fleet gasoline: 422,431 GJ ■ Jet fuel: 16,572 GJ ■ Stationary diesel: 147,791 GJ ■ Propane: 20,996 GJ ■ Natural gas: 188,249 GJ ■ Electricity: 28,101,877 GJ Standards, methodologies, assumptions, and/or calculation tools used: Energy consumption data is collected, calculated, and reported in accordance with the GHG Protocol and T-Mobile’s standard procedures and guidelines for sustainability reporting. All energy consumption data is verified annually by an independent third party to the International Standard on Assurance Engagements (ISAE) 3000 (Revised) standard. All energy consumption that is designated to be within T-Mobile’s operational control is included. Most data is historical in nature and based on primary data. Estimation methodologies are used for a small number of sites where primary data is not available. Source of the conversion factors used: Publicly available conversion factors from the U.S. Environmental Protection Agency (EPA) and the International Panel on Climate Change (IPCC) are used to convert from the native unit of measure (gallons or mmBTU) to MWh. Standard and recognizable conversion factors are used to convert from MWh to GJ (x * 3.600). Conversions: ■ U.S. EPA Center for Corporate Climate Leadership: “Emission Factors for Greenhouse Gas Inventories”, (2020) ■ IPCC: “2006 IPCC Guidelines for National Greenhouse Gas Inventories”, (2006) For more information, refer to our latest CDP Climate Change response and our third-party Assurance Statement on our reporting page . GRI Index Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT 75 OUR COMPANY

Disclosure# Disclosure Topic 2021 Response 302-2 Energy consumption outside of the organization Energy consumption outside of the organization, in joules or multiples: 7,875,945 GJ Standards, methodologies, assumptions, and/or calculation tools used: Downstream customer energy consumption data is estimated based on device-specific LCA data and in accordance with the GHG Protocol Corporate Value Chain (scope 3) Standard. Source of the conversion factors used: Standard and recognizable conversion factors are used to convert from MWh to GJ (x * 3.600). 302-3 Energy intensity Energy intensity ratio for the organization: 349.39 MWh/PB Organization-specific metric (the denominator) chosen to calculate the ratio: Total petabytes (PB) of network traffic for calendar year 2021 Types of energy included in the intensity ratio; whether fuel, electricity, heating, cooling, steam, or all: All energy in MWh Whether the ratio uses energy consumption within the organization, outside of it, or both: Within the organization For more information, refer to our latest CDP Climate Change response on our reporting page . 302-4 Reduction of energy consumption Amount of reductions in energy consumption achieved as a direct result of conservation and efficiency initiatives, in joules or multiples: 2,025,485 GJ Types of energy included in the reductions; whether fuel, electricity, heating, cooling, steam, or all: Electricity Basis for calculating reductions in energy consumption, such as base year or baseline, including the rationale for choosing it: The energy consumption in the year prior to the implementation of the conservation and efficiency initiatives is used as the baseline. Standards, methodologies, assumptions, and/or calculation tools used: Energy reduction data is collected, calculated, and reported in accordance with the most recent CDP Climate Change Reporting Guidance for Emissions Reduction Initiatives (C4.3). For more information, refer to our latest CDP Climate Change response on our reporting page . Material Topic: Natural Resources Management and Conservation GRI 303: Water and Effluents 103-1 Explanation of the material topic and its Boundaries 2021 Corporate Responsibility Report: Our Company > ESG Approach 2021 Corporate Responsibility Report: The Numbers and Small Print > Material Topic Definitions While T-Mobile uses relatively little water compared to companies in many other industries, we strive to use it in a responsible and sustainable manner to help conserve this important natural resource. Our reporting for water consumption includes domestic water used in our buildings (data centers, call centers, offices, retail stores, switches, warehouse), some cell sites with irrigation, as well as domestic wastewater. We do not include water use for buildings where the water utility is not included in the leasing contracts. 103-2 The management approach and its components 2021 CORPORATE OUR OUR OUR THE THE NUMBERS RESPONSIBILITY REPORT GOVERNANCE PEOPLE COMMUNITIES ENVIRONMENT AND SMALL PRINT GRI Index Continued Environmental Policy 2021 Corporate Responsibility Report: The Environment > Natural Resources Management 76 OUR COMPANY

Disclosure# Disclosure Topic 2021 Response 103-3 Evaluation of the management approach 2021 Corporate Responsibility Report: Our Company > ESG Approach 303-1 Interactions with water as a shared resource (management approach disclosures) T-Mobile employee occupied buildings across the United States, interacting with domestic water use (includes data centers, call centers, offices, stores, switches, warehouses), and some cell sites with irrigation through our direct operations. Water withdrawal and discharge occurs through the different municipal systems in the United States. As outlined by our Responsible Sourcing Guidelines , we show a preference for working with suppliers who demonstrate adherence to industry best practices in areas such as water use. 303-2 Management of water discharge-related impacts (management approach disclosures) We manage our domestic wastewater released through the sewage system of our buildings according to each municipal water treatment system standard. We therefore follow all local municipal wastewater treatment protocols for domestic water discharge from our facilities. 303-5 Water consumption In 2021, T-Mobile used 1,054,583 cubic meters (m 3 ) of water. This includes the municipal water withdrawal that we are directly billed for in our buildings (data centers, customer experience centers, offices, retail stores, switches, warehouse), and some cell sites with irrigation. Material Topic: Greenhouse Gas Emissions and Climate Change GRI 305: Emissions 103-1 Explanation of the material topic and its Boundaries 2021 Corporate Responsibility Report: Our Company > ESG Approach 2021 Corporate Responsibility Report: The Numbers and Small Print > Material Topic Definitions 103-2 The management approach and its components Environmental Policy CDP Climate Change Response 2021 Corporate Responsibility Report: The Environment > Climate Change 103-3 Evaluation of the management approach 2021 Corporate Responsibility Report: Our Company > ESG Approach GRI Index Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT 77 OUR COMPANY

Disclosure# Disclosure Topic 2021 Response 305-1 Direct (scope 1) GHG emissions Gross direct (scope 1) GHG emissions in metric tons of CO 2 equivalent: 70,350 MT CO 2 e Gases included in the calculation: CO 2 , CH 4 , N 2 O , HFCs Biogenic CO 2 emissions in metric tons of CO 2 equivalent: 0 MT CO 2 e Base year for the calculation: 2016 ■ The rationale for choosing it: 2016 was the first year of available data for all direct emissions sources across the T-Mobile and Sprint portfolios ■ Emissions in the base year: 61,266 MT CO 2 e ■ The context for any significant changes in emissions that triggered recalculations of base year emissions: The 2016 emissions figures for T-Mobile and Sprint were combined to ensure consistency when comparing base year emissions to current and future reporting periods Source of the emission factors and the global warming potential (GWP) rates used, or a reference to the GWP source: Publicly available emission factors and global warming potential values from the U.S. Environmental Protection Agency (EPA) and the International Panel on Climate Change (IPCC) are used to convert from the native unit of measure (gallons, mmBTU, or MWh) to MT CO 2 e . Emission factors: ■ U.S. EPA Center for Corporate Climate Leadership: “Emission Factors for Greenhouse Gas Inventories”, (2020) 100-year global warming potential values: ■ IPCC: “Fifth Assessment Report (AR5)”, (2014) Consolidation approach for emissions: Operational control Standards, methodologies, assumptions, and/or calculation tools used: scope 1 emissions data is collected, calculated, and reported in accordance with the GHG Protocol and T-Mobile’s standard procedures and guidelines for sustainability reporting. All scope 1 emissions data is verified annually by an independent third party. All scope 1 emissions from sources designated to be within T-Mobile’s operational control are included. All data is historical in nature and based on primary data. For more information, refer to our most recent CDP Climate Change response on our reporting page . GRI Index Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT 78 OUR COMPANY

Disclosure# Disclosure Topic 2021 Response 305-2 Energy indirect (scope 2) GHG emissions Gross location-based energy indirect (scope 2) GHG emissions in metric tons of CO 2 equivalent: 2,893,728 MT CO 2 e Gross market-based energy indirect (scope 2) GHG emissions in metric tons of CO 2 equivalent: 0 MT CO 2 e Gases included in the calculation: CO 2 , CH 4 , N 2 O Base year for the calculation: 2016 ■ The rationale for choosing it: 2016 was the first year of available data for all indirect emissions sources across the T-Mobile and Sprint portfolios ■ Emissions in the base year: Location-Based & Market-Based: 2,395,646 MT CO 2 e ■ The context for any significant changes in emissions that triggered recalculations of base year emissions: The 2016 emissions figures for T-Mobile and Sprint were combined to ensure consistency when comparing base year emissions to current and future reporting periods Source of the emission factors and the global warming potential (GWP) rates used, or a reference to the GWP source: Publicly available emission factors and global warming potential values from the U.S. Environmental Protection Agency (EPA) and the International Panel on Climate Change (IPCC) are used to convert from the native unit of measure (MWh) to MT CO 2 e . Emission factors: ■ U.S. EPA: “Emissions & Generation Resource Integrated Database (eGRID) Summary Tables 2019”, (2021) 100-year global warming potential values: ■ IPCC: “Fifth Assessment Report (AR5)”, (2014) Consolidation approach for emissions: Operational control Standards, methodologies, assumptions, and/or calculation tools used: scope 2 emissions data is collected, calculated, and reported in accordance with the GHG Protocol and T-Mobile’s standard procedures and guidelines for sustainability reporting. All scope 2 emissions data is verified annually by an independent third party. All scope 2 emissions from sources designated to be within T-Mobile’s operational control are included. Most data is historical in nature and based on primary data. Estimation methodologies are used for a small number of sites where primary data is not available. For more information, refer to our most recent CDP Climate Change response on our reporting page . GRI Index Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT 79 OUR COMPANY

Disclosure# Disclosure Topic 2021 Response 305-3 Other indirect (scope 3) GHG emissions Gross other indirect (scope 3) GHG emissions in metric tons of CO 2 equivalent: 7,263,741 MT CO 2 e Gases included in the calculation: CO 2 , CH 4 , N 2 O Biogenic CO 2 emissions in metric tons of CO 2 equivalent: 0 MT CO 2 e Other indirect (scope 3) GHG emissions categories and activities included in the calculation: ■ Purchased goods and services ■ Capital goods ■ Fuel and energy-related activities ■ Upstream transportation and distribution ■ Waste generated in operations ■ Business travel ■ Employee commuting ■ Downstream transportation and distribution ■ Use of sold products ■ End-of-life treatment of sold products Base year for the calculation: 2016 ■ The rationale for choosing it: 2016 was the first year of available data for all indirect emissions sources across the T-Mobile and Sprint portfolios ■ Emissions in the base year: 7,046,768 MT CO 2 e ■ The context for any significant changes in emissions that triggered recalculations of base year emissions: The 2016 emissions figures for T-Mobile and Sprint were combined to ensure consistency when comparing base year emissions to current and future reporting periods Source of the emission factors and the global warming potential (GWP) rates used, or a reference to the GWP source: A mix of publicly available and internal emission factors are used to convert from the various native units of measure to MT CO 2 e. Supplier-specific emission factors are collected on a unit volume and revenue basis and are used whenever possible. Emission Factors: ■ U.S. EPA: “Emissions & Generation Resource Integrated Database (eGRID) Summary Tables 2019”, (2021) 100-year global warming potential values: ■ IPCC: “Fifth Assessment Report (AR5)”, (2014) ■ Ecoinvent: “Version 3”, (2013-2020) ■ CDP Supply Chain: Supplier-specific emission factors, (2020) ■ Apple: “Product Environmental Report”—Various Models, (2018-2021) ■ Green Design Institute: “US 2002 Benchmark Model—purchaser price”, (2010) Standards, methodologies, assumptions, and/or calculation tools used: scope 3 emissions data is collected, calculated, and reported in accordance with the GHG Protocol and T-Mobile’s standard procedures and guidelines for sustainability reporting. All scope 3 emissions data is verified annually by an independent third party. Most scope 3 data is historical in nature and based on primary data or expenditure data. Estimation methodologies based on internal studies and data are used for some scope 3 calculations where primary data is not available. For more information, refer to our most recent CDP Climate Change response on our reporting page . 305-4 GHG emissions intensity GHG emissions intensity ratio for the organization: 319.18 MT CO 2 e /PB Organization-specific metric (the denominator) chosen to calculate the ratio: Total petabytes (PB) of network traffic for calendar year 2021 Types of GHG emissions included in the intensity ratio: scope 1, scope 2 (market-based), scope 3 Gases included in the calculation: CO 2 , CH 4 , N 2 O , HFCs For more information, refer to our most recent CDP Climate Change response on our reporting page . GRI Index Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT 80 OUR COMPANY

Disclosure# Disclosure Topic 2021 Response 305-5 Reduction of GHG emissions GHG emissions reduced as a direct result of reduction initiatives, in metric tons of CO 2 equivalent: 937,965 MT CO 2 e Gases included in the calculation: CO 2 , CH 4 , N 2 O Base year or baseline, including the rationale for choosing it: The GHG emissions in the year prior to the implementation of the reduction initiatives is used as the baseline. Scopes in which reductions took place; whether direct (scope 1), energy indirect (scope 2), and/or other indirect (scope 3): scope 2 and scope 3 Standards, methodologies, assumptions, and/or calculation tools used: GHG emissions reduction data is collected, calculated, and reported in accordance with the GHG Protocol and the most recent CDP Climate Change Reporting Guidance for Emissions Reduction Initiatives (C4.3). For more information, refer to our most recent CDP Climate Change response on our reporting page . Material Topic: Waste and Recycling GRI 306: Waste 103-1 Explanation of the material topic and its Boundaries 2021 Corporate Responsibility Report: Our Company > ESG Approach 2021 Corporate Responsibility Report: The Numbers and Small Print > Material Topic Definitions 103-2 The management approach and its components Environmental Policy CDP Climate Change Response 2021 Corporate Responsibility Report: The Environment > Waste and Recycling 103-3 Evaluation of the management approach 2021 Corporate Responsibility Report: Our Company > ESG Approach 306-1 Waste generation and significant waste-related impacts T-Mobile manages its operational waste in an environmentally responsible manner, including Municipal Solid Waste (MSW), regulated waste, shred paper, and electronic waste. We manage impacts related to waste generated in our own activities. GRI Index Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES 81 OUR COMPANY THE ENVIRONMENT THE NUMBERS AND SMALL PRINT

Disclosure# Disclosure Topic 2021 Response 306-2 Management of significant waste- related impacts Universal Regulated Waste: T-Mobile works with a single national vendor to provide universal regulated waste collection across the company. This includes collection for dry cell batteries, bulbs, ballasts, aerosol cans, and some small electronics. All corporate owned retail stores have regulated waste collection centers on site to ensure accessible collection. Employees and contractors at other locations can also request vendor universal regulated waste collection supplies from a T-Mobile internal web portal. Document Shredding: T-Mobile provides secure document shredding at retail and commercial real estate offices. For employees at our Overland Park, Kansas office, shred paper collection events are held monthly at no charge to employees. E-waste: T-Mobile works to responsibly manage electronic waste across our operations, which includes IT and network equipment. We also provide opportunities for customers to responsibly dispose of their devices. Our device recycling and reuse program aims to recover devices, such as phones, smartwatches, tablets, hotspots, and IoT items. Municipal Solid Waste: Trash and recycling services are provided at our buildings according to local regulations and guidelines outlined by building owners. Hazardous waste: T-Mobile works with select vendors to responsibly manage hazardous waste and dispose of it in accordance with applicable laws and regulations. Third-party waste management and oversight processes: T-Mobile works with a third-party waste diversion consultant to optimize recycling best practices. In addition, the third-party waste diversion consultant audits service provided by our two national haulers to right-size those services and validate they match the contracted agreement. We are also a member of the Department of Energy’s Better Buildings Waste Pilot in an effort to share and learn best practices for waste diversion, reporting, and employee engagement and education. Processes used to collect and monitor waste-related data: We receive waste reports from select vendors, including national haulers and recyclers for select waste streams. 306-3 Waste generated Total Waste: 40,606.18 metric tons (MT) ■ Municipal Solid Waste: 12,533.31 ■ Hazardous and Non-hazardous Waste: 17.34 ■ Compost: 0.90 ■ Mixed Recyclables and Regulated Waste: 8,323.01 ■ Paper Shred: 2,923.32 ■ IT Equipment: 567.04 ■ Network Equipment: 16,236.90 ■ Handsets and Tablets (excludes customer devices): 4.36 306-4 Waste diverted from disposal T-Mobile generated approximately 28,055 metric tons of waste that was diverted from disposal. 306-5 Waste directed to disposal T-Mobile generated approximately 12,550 metric tons of non-diverted waste, largely consisting of municipal solid waste and a limited amount (approximately 0.1%) of non-hazardous and hazardous waste responsibly managed by approved vendors in accordance with applicable laws and regulations. 82 GRI Index Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES OUR COMPANY THE ENVIRONMENT THE NUMBERS AND SMALL PRINT

Disclosure# Disclosure Topic 2021 Response Social Disclosures Material Topic: Health, Safety, and Wellness GRI 403: Occupational Health and Safety 103-1 Explanation of the material topic and its Boundaries 2021 Corporate Responsibility Report: Our Company > ESG Approach 2021 Corporate Responsibility Report: The Numbers and Small Print > Material Topic Definitions 103-2 The management approach and its components 2021 Corporate Responsibility Report: Our People > Health, Safety, and Wellness T-Mobile’s Environmental, Health, and Safety (EHS) Policies and Standards apply to all T-Mobile operations and subsidiaries. At T-Mobile, we work hard to reduce workplace hazards, comply with all applicable environmental, health, and safety regulations, and implement sustainable business practices. Underpinning our commitment to maintain a safe and healthy workplace and to minimize the impact of business operations on the environment, is our Environmental, Health, and Safety (EHS) Program. Our EHS Program includes current EHS Policies and Standards within a Company EHS Management System that apply to all T-Mobile operations and subsidiaries. 103-3 Evaluation of the management approach 2021 Corporate Responsibility Report: Our Company > ESG Approach The EHS team identifies gaps and implements programs needed to ensure ongoing compliance and continuous improvement of the EHS Management System. This team is overseen by executive leadership and works closely with business units and supervisors across the company to ensure integration of EHS requirements and ongoing reporting of EHS activities. 403-1 Occupational health and safety management system T-Mobile’s EHS Management System is a set of interrelated programs and policies designed to implement, operate, monitor, and improve standards and processes that ensure ongoing compliance and to reduce workplace hazards and environmental impacts. T-Mobile’s EHS Management System is aligned to International Standard Organization (ISO) 14001 (Environmental Management Systems) and ISO 45001 (Occupational Health and Safety Management Systems). Scope of program is all sites enterprise-wide. 403-2 Hazard identification, risk assessment, and incident investigation The EHS team is comprised of experienced professionals who develop, coordinate implementation, monitor, review, and maintain EHS programs to reduce workplace hazards and environmental impacts. The EHS team is overseen by executive leadership and works closely with business units and supervisors across the company to ensure integration of EHS requirements and ongoing reporting of EHS activities. T-Mobile’s EHS program outlines hazard prevention requirements and controls, emergency response plans, medical assistance protocols, awareness and training requirements, and the process for incident reporting and investigations. All EHS-related incidents must be reported via an appropriate mechanism (e.g. the EHS email box, EHS hotline, or the incident management system) according to the Code of Business Conduct. For more information, please contact Safety@T-mobile.com . All unsafe conditions are to be immediately reported to management. Employees can phone concerns to the 24/7 EHS Helpline at 877-604-7233 or email them to Safety@T-Mobile.com. Work-related incidents are filed in the Aurora incident reporting system with immediate distribution to EHS, Risk Management/Insurance, and Site Safety. Upon receipt of facts, an incident investigation is commenced. GRI Index Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES 83 OUR COMPANY THE ENVIRONMENT THE NUMBERS AND SMALL PRINT

Disclosure# Disclosure Topic 2021 Response 403-3 Occupational health services The EHS team partners with line of business leadership to manage EHS risk across the enterprise and to ensure implementation of applicable EHS Enterprise Programs. This includes program development, change management, regulatory updates, site assessments, training, incident investigation, metric development and reporting, and interfacing with regulators. The EHS team identifies gaps and implements programs needed to ensure ongoing compliance and continuous improvement of the EHS Management System. The EHS team works with Safety Lead Employees, who are responsible for the implementation and management of EHS Enterprise Programs that apply to their lines of business, and Site Leads, who manage EHS processes and procedures at their sites, implement EHS Enterprise Programs, communicate EHS program information, and review EHS issues with the local Safety Committee. Supervisors are responsible for EHS program adherence for their area of authority. T-Mobile maintains a centralized electronic repository for company-wide access to EHS program documents. 403-4 Worker participation, consultation, and communication on occupational health and safety T-Mobile maintains a centralized electronic repository for company-wide access to EHS program documents. All T-Mobile employees receive Company Safety Training and Enterprise Emergency Procedures. In addition, T-Mobile requires training and instruction on general and job-specific EHS practices as appropriate. In addition, safety committees are formed for any non-retail facility with more than ten employees in order to provide a forum to regularly discuss and address local workplace hazards, reduce workplace EHS risks, and promote health and safety awareness. For facilities with ten or fewer employees, the senior manager at the facility includes EHS issues as a recurring topic during staff meetings. 403-5 Worker training on occupational health and safety All T-Mobile employees receive Company Safety Training and Enterprise Emergency Procedures. In addition, T-Mobile requires training and instruction on general and job-specific EHS practices as appropriate, which includes: ■ New job assignment EHS training; ■ EHS training for whenever new substances, processes, procedures, or equipment are introduced to the workplace and present a new hazard; ■ EHS training for whenever the facility is made aware of a new or previously unrecognized hazard; ■ Manager-led instruction for employees under their direction that includes the safety and health hazards to which they may be exposed; ■ First aid, cardiopulmonary resuscitation (CPR), and bloodborne pathogen certification training for all telecommunications field workers; and ■ Other training as required to ensure the health and welfare of employees (e.g., ladder training, fire extinguisher, etc.). 403-6 Promotion of worker health 2021 Corporate Responsibility Report: Our People > Health, Safety, and Wellness Read about our benefits on our website: Employee Benefits 403-7 Prevention and mitigation of occupational health and safety impacts directly linked by business relationships 2021 CORPORATE OUR OUR OUR RESPONSIBILITY REPORT GOVERNANCE PEOPLE COMMUNITIES GRI Index Continued T-Mobile has a well-defined Contractor Safety Program, which works to ensure more than 1,000 key vendors have the proper health and safety programs in place to prevent workplace incidents while doing work on behalf of T-Mobile. All such programs must be uploaded into a third-party database, and key safety metrics from the past three years are entered, and then reviewed by the EHS team. If vendors do not meet T-Mobile’s criteria, they are not authorized to do work on T-Mobile’s behalf. 84 OUR COMPANY THE ENVIRONMENT THE NUMBERS AND SMALL PRINT

Disclosure# Disclosure Topic 2021 Response 403-9 Work-related injuries For T-Mobile employees: ■ The number of fatalities: 0 ■ The rate of fatalities: 0 ■ The number and rate of high-consequence work-related injuries (excluding fatalities): 3 and 0.004 per 200,000 hours worked ■ The number and rate of recordable work-related injuries: 183 and 0.27 per 200,000 hours worked ■ The main types of work-related injury: Slips/trips/falls, struck against/by object, and strains/sprains ■ The number of hours worked: 135,318,647 hours For all workers who are not employees but whose work and/or workplace is controlled by the organization: Such figures for non-T-Mobile employees are not tracked as T-Mobile is not a controlling entity for on-site safety. In addition, T-Mobile employees are not authorized for high-risk/high-consequence tasks. All such tasks (such as tower climbing, high voltage electrical work) would be completed by a qualified third-party entity that is evaluated holistically by T-Mobile’s Contractor Safety Program. Whether the rates have been calculated based on 200,000 or 1,000,000 hours worked: 200,000 hours worked. Whether and, if so, why any workers have been excluded from this disclosure, including the types of worker excluded: No exclusions of T-Mobile employees. Material Topic: Employee Engagement, Learning, and Development GRI 404: Training and Education 103-1 Explanation of the material topic and its boundaries 2021 Corporate Responsibility Report: Our Company > ESG Approach 2021 Corporate Responsibility Report: The Numbers and Small Print > Material Topic Definitions 103-2 The management approach and its components 2021 Corporate Responsibility Report: Our People > Employee Engagement, Learning, and Development 103-3 Evaluation of the management approach 2021 Corporate Responsibility Report: Our Company > ESG Approach 404-1 Average hours of training per year per employee Employees participated in over 5.4 million hours of training. This number includes only those trackable training hours completed in a formal Learning Management System by all T-Mobile full- and part-time employees. GRI Index Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES 85 OUR COMPANY THE ENVIRONMENT THE NUMBERS AND SMALL PRINT

Disclosure# Disclosure Topic 2021 Response 404-2 Programs for upgrading employee skills and transition assistance programs Learning and Development Highlights: ■ Employees participated in approximately 5.4 million hours * of training ■ We provided $20.18 million in tuition assistance for 5,803 employees ■ Our Day of Learning reached more than 15,700 employees, employees rated it 4.3 out of 5 stars and 70% would recommend a replay to their peers ■ Our 2021 CareerFest event reached more than 8,700 employees ■ The 2021 Apprenticeship program had a 100% conversion/retention rate for those that completed the program ■ Lead Magenta Next was recognized as the i4cp Next Practice Winner in 2021 ■ 311 joined leadership and career development programs focused on opportunities to enhance capabilities of underrepresented talent At T-Mobile, our people come first, and we won’t stop helping employees achieve their goals. We have a robust lineup of development programs and resources designed to build a diverse group of leaders and empower employees for career success. We are on a mission to deliver learning and create connections across the enterprise for ALL employees to continually evolve their skills and careers so we can achieve something bigger and better together. And, it’s all easily accessible on our Magenta University site, which is our one-stop shop for all things career development and learning. Magenta University helps employees evolve their skills and career, advance leadership expertise, and deepen commitments to DE&I. * Includes only trackable training hours completed in our formal Learning Management System. Material Topic: Employee Diversity (Equity and Inclusion) GRI 405: Diversity and Equal Opportunity 103-1 Explanation of the material topic and its Boundaries 2021 Corporate Responsibility Report: Our Company > ESG Approach 2021 Corporate Responsibility Report: The Numbers and Small Print > Material Topic Definitions 103-2 The management approach and its components Human Rights Statement 2021 Corporate Responsibility Report: Our People > DE&I 103-3 Evaluation of the management approach 2021 Corporate Responsibility Report: Our Company > ESG Approach 405-1 Diversity of governance bodies As of December 31, 2021, our 14-member Board included: 4 women (28.6%) 4 people who belong to a traditionally underrepresented racial/ethnic group (28.6%) Percent between 30-50 years old: 7% Percent above 50 years old: 93% GRI Index Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES 86 OUR COMPANY THE ENVIRONMENT THE NUMBERS AND SMALL PRINT

Disclosure# Disclosure Topic 2021 Response Diversity of employees 2021 Corporate Responsibility Report: Our People > DE&I 2021 Corporate Responsibility Report: Our Governance > Corporate Governance Material Topic: Digital Security and Privacy GRI 418: Customer Privacy 103-1 Explanation of the material topic and its Boundaries 2021 Corporate Responsibility Report: Our Company > ESG Approach 2021 Corporate Responsibility Report: The Numbers and Small Print > Material Topic Definitions 103-2 The management approach and its components 2021 Corporate Responsibility Report: Our Governance > Data Privacy 103-3 Evaluation of the management approach 2021 Corporate Responsibility Report: Our Company > ESG Approach 418-1 Substantiated complaints concerning breaches of customer privacy and losses of customer data T-Mobile does not report on all complaints concerning customer privacy or data loss. As required by FCC rules, T-Mobile has implemented policies and procedures to capture (and investigate) all customer complaints made to any company business channel (e.g., customer care, retail, Web, etc.) concerning alleged unauthorized release of CPNI. We report this number (for both substantiated and unsubstantiated complaints) annually to the FCC in a public filing available from T-Mobile or from the FCC’s website under Docket 06-36. For 2021, that filing reported a total of 913 complaints concerning CPNI (some of which were determined not to be substantiated). GRI Index Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES 87 OUR COMPANY THE ENVIRONMENT THE NUMBERS AND SMALL PRINT

SASB Index SASB Index The table below references the Sustainability Accounting Standards Board (SASB) Standards for the Telecommunication Services Industry, as defined by SASB’s Sustainable Industry Classification System. Topic SASB Code Requested Metric 2021 Response Environmental Footprint of Operations T C -T L- 1 3 0 a .1 (1) Total energy consumed 28,902,225 GJ Total energy consumed is calculated based on emissions sources included in scope 1 and 2 GHG emissions, namely diesel, gasoline, jet fuel, propane, natural gas, and electricity. For more information, refer to our Independent Assurance Statement, which can be found on our reporting page . T C -T L- 1 3 0 a . 2 (2) Percentage grid electricity 9 7. 2 % Percentage grid electricity is calculated as total electricity consumed as purchased from the grid (and reported for scope 2 GHG emissions) divided by total energy consumed. T C -T L- 1 3 0 a . 3 (3) Percentage renewable 9 7. 2 % Percentage renewable electricity is calculated as total renewable electricity generated on site or purchased in the form of renewable energy credits divided by total energy consumed. 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES 88 OUR COMPANY THE ENVIRONMENT THE NUMBERS AND SMALL PRINT

Topic SASB Code Requested Metric 2021 Response Data Privacy T C -T L-2 2 0 a .1 Description of policies and practices relating to behavioral advertising and customer privacy The T-Mobile Privacy Center houses our Privacy Notices about our privacy practices for consumers. Here consumers can find the choices they have over the use of their personal data and our Privacy Notice describing what data we collect, how it is used, when it is shared, how we retain and protect it, and other privacy safeguards. See the T-Mobile Privacy Notice for how the company collects, uses, shares, and protects personal data. T-Mobile has policies and practices in place for data handling and to govern the data lifecycle including the use of Privacy by Design principles and processes to evaluate new projects using Privacy Impact Assessments. We don’t knowingly collect data from or about children without the permission of their parent or guardian. When we do collect that data, we might do it directly, like when they sign up for a service. We might also collect it automatically if a child uses the products or services we offer. See our Children’s Privacy Notice for more information. The T-Mobile Privacy Center gives consumers easy to access information concerning behavioral advertising and their choices. This includes the choices consumers have over the use of their personal data for relevant advertising and data analytics and reporting. For more information see our Advertising and Analytics article . For relevant ads, T-Mobile will use and analyze data from your device, and usage data generated by use of T-Mobile products and services, and sometimes data from third-party partners, to create inferences for our own and third-party advertising until customers tell us not to use it. This data helps us understand more about user interests (e.g. sports enthusiast, loves cooking, etc.). This data does not directly identify users. T C -T L-2 2 0 a . 2 Number of customers whose information is used for secondary purposes The number of customers whose information is used for secondary purposes varies by product as consumers may opt out of these uses. For example, we offer consumer choices about data use for analytics and reporting or relevant advertising. We publicly disclose information on the types of secondary uses in our Privacy Notice as well as the number of requests we’ve received from customers to access or delete their personal data, or opt-out. T C -T L-2 2 0 a . 3 Total amount of monetary losses as a result of legal proceedings associated with customer privacy For purposes of reporting this metric, we’ll report on regulatory fines or legal settlements for matters that have a material impact on our operations, or which we’d otherwise disclose to investors pursuant to SEC guidance. We do not, as of this report, have any material monetary loss as the result of litigation or regulatory investigations concerning our processing of consumer data. T C -T L-2 2 0 a . 4 (1) Number of law enforcement requests for customer information (2) Number of customers whose information was requested (3) Percentage resulting in disclosure T-Mobile discloses the number of law enforcement requests for customer information and the number of requests that were rejected, received no response, or received a written explanation of why T-Mobile was unable to respond in whole or in part. For the latest annual figures, visit our website to view the most current annual Transparency Report. T-Mobile releases customer records to third parties only when legally authorized or compelled to do so. Our Legal and Emergency Response team relies on Federal and State statutes and regulations when determining appropriate compliance. The Legal and Emergency Response Specialists are trained to analyze legal demands and make a determination regarding appropriate compliance. Generally, T-Mobile notifies customers of third-party legal demands only if required by law or contract to do so. T-Mobile does not measure the number of individual customers whose information is requested. SASB Index Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES 89 OUR COMPANY THE ENVIRONMENT THE NUMBERS AND SMALL PRINT

Topic SASB Code Requested Metric 2021 Response Data Security T C -T L-2 3 0 a .1 (1) Number of data breaches (2) Percentage involving personally identifiable information (PII) (3) Number of customers affected T-Mobile does not report these figures publicly, in part as the definition of “data breach” varies across laws and contract terms. We do provide public notice for those incidents where such notice is required by law. In unusual cases, we may provide additional information about an incident and our response. T C -T L-2 3 0 a . 2 Description of approach to identifying and addressing data security risks, including use of third-party cybersecurity standards We use administrative, technical, contractual, and physical safeguards designed to protect customer data while it is under our control. T-Mobile’s data security program also includes, among other items, a threat intelligence component, a supplier risk management component, a vulnerability and patch management component, and investigative tools such as digital loss prevention tools to identify and address data security risks. We utilize the National Institute of Standards and Technology (NIST) Cybersecurity Framework in designing that program and comply with applicable data security laws and standards in the context where they apply. Examples of such laws and standards include the Sarbanes-Oxley law on financial reports, FCC CPNI rules for certain telecommunications usage data, Payment Card Industry standards applicable to handling of payment card data, and the Cybersecurity Maturity Model Certification (CMMC) for certain federal service contracts. Product End-of-life Management T C -T L- 4 4 0 a .1 (1) Materials recovered through take- back programs Percentage of recovered materials that were (2) reused Percentage of recovered materials that were (3) recycled Percentage of recovered materials that were (4) landfilled T-Mobile is committed to giving customers a way to responsibly dispose of their devices and extend their product life. Through our Device Reuse and Recycling program, customers can trade in an eligible device for a credit toward a new one or they can bring in unused devices to our retail collection sites. Devices currently included in this program include phones, smartwatches, tablets, hotspots, and IoT items. Our Device Reuse and Recycling program complies with federal and state laws and gives consumers a way to properly and safely recycle these items. T-Mobile requires suppliers and partners that repair and recycle these devices to be certified to the industry-leading R2 standard which provides a common set of processes, safety measures, and documentation requirements. R2 is rigorously and independently audited, emphasizing quality, safety, and transparency, including any devices exported for refurbishment and recycling. In 2021, T-Mobile collected approximately 11.6 million devices (5,388 MT) through this take-back program. As of 12/31/21, approximately 90% were reused or resold to approved vendors for reuse, approximately 3% responsibly recycled by certified third-party facilities, and approximately 6% remained in inventory and are intended to be reused or recycled in 2022. SASB Index Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES 90 OUR COMPANY THE ENVIRONMENT THE NUMBERS AND SMALL PRINT

Topic SASB Code Requested Metric 2021 Response Competitive Behavior & Open Internet T C -T L- 5 2 0 a .1 Total amount of monetary losses as a result of legal proceedings associated with anti-competitive behavior regulations For the fiscal year 2021, T-Mobile had no material losses related to litigation or to non-appealable regulatory decisions involving anti-competitive behavior. T C -T L- 5 2 0 a . 2 Average actual sustained download speed of (1) owned and commercially- associated content and (2) non- associated content T-Mobile is committed to an open internet and does not directly or indirectly favor some traffic over other traffic either in exchange for consideration from a third party or to benefit an affiliated entity. For more information on T-Mobile network performance characteristics (including download speeds), customer options, and network management practices, see our Open Internet information page online. TC-TL-520a.3 Description of risks and opportunities associated with net neutrality, paid peering, zero rating, and related practices See T-Mobile’s SEC reports for our disclosures relating to the risks and opportunities associated with laws and regulations addressing net neutrality. Managing Systemic Risks from Technology Disruptions TC-TL-550a.1 (1) System average interruption frequency (2) Customer average interruption duration T-Mobile does not currently disclose the system average interruption frequency. T-Mobile does not currently disclose the customer average interruption duration. TC-TL-550a.2 Discussion of systems to provide unimpeded service during service interruptions At T-Mobile, we understand the importance of reliable communications and connectivity during critical events, like natural disasters and emergency situations. That’s why building in operational and network resilience is vital to the work we do. As a company, we are committed to safeguarding the interests of our customers, employees, and stakeholders in the event of an emergency or significant business disruption. We maintain an Enterprise Continuity Program designed to be best-in-class with proactive measures to reduce risk to enterprise operations and recovery solutions that minimize impact to customers and services during a potential business disruption. With enterprise-wide teams that work to address business continuity, disaster recovery, network availability, emergency response, and customer support, we are relentless at keeping the interests of our customers, employees, and stakeholders at the forefront of our disaster readiness and emergency response work. A team of dedicated, certified, and seasoned business continuity professionals work with all lines of business to help ensure that Business Continuity Plans are current, comprehensive, and effective. Critical operations, processes, and services across the enterprise are identified along with criticality ratings, risks, gaps, and potential impacts of a service disruption. Process, criticality, and risk reviews are conducted on a regular basis. T-Mobile’s Executive Management receives a quarterly risk report inclusive of the efforts and status of the Enterprise Continuity Program. The Enterprise Continuity Program is also reviewed and approved by leadership on an annual basis. SASB Index Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES 91 OUR COMPANY THE ENVIRONMENT THE NUMBERS AND SMALL PRINT

Topic SASB Code Requested Metric 2021 Response Number of Wireless Subscribers TC-TL-000.A Quantitative T-Mobile reported 108,719,000 wireless customers at the end of 2021. A customer is generally defined as a SIM number with a unique T-Mobile identifier which is associated with an account that generates revenue. Customers are qualified either for postpaid service utilizing phones, High Speed Internet, wearables, DIGITS, or other connected devices, which include tablets and SyncUP products, where they generally pay after receiving service, or prepaid service, where they generally pay in advance of receiving service. Our postpaid customers include customers of T-Mobile. Our prepaid customers include customers of T-Mobile and Metro by T-Mobile. Number of Wireline Subscribers TC-TL-000.B Quantitative T-Mobile does not have customers who contract with us for fixed line phone services as outlined by the standard. Number of Broadband Subscribers TC-TL-000.C Quantitative T-Mobile reported 646,000 High Speed Internet customers at the end of 2021. Network Traffic TC-TL-000.D Quantitative T-Mobile does not currently report this information. SASB Index Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES 92 OUR COMPANY THE ENVIRONMENT THE NUMBERS AND SMALL PRINT

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