OUR PURPOSE PIONEERING SCIENCE 132 BIOGEN 2021 YEAR IN REVIEW PATIENTS OUR PEOPLE ENVIRONMENT COMMUNITY REPORTING GRI indicator Reporting Requirements 2021 Response Alignment SDG GRI 102 GENERAL DISCLOSURES Organizational profile 102–1 Name of the organization Biogen Inc. 102–2 a. A description of the organization’s activities. b. Primary brands, products and services, including an explanation of any products or services that are banned in certain markets. CEO Letter – 2021 Year in Review Item 1., Business, 2021 Annual Report 102–3 Location of the organization’s headquarters. Corporate Headquarters: Cambridge, Massachusetts (U.S.) 102–4 Number of countries where the organization operates, and the names of countries where it has significant operations and/or that are relevant to the topics covered in the report. Pharmaceutical Operations & Technology Item 2., Properties, 2021 Annual Report 102–5 Nature of ownership and legal form. Board of Directors Corporate Governance Documents 102–6 Markets served, including: • Geographic locations where products and services are offered. • Sectors served. • Types of customers and beneficiaries. Item 1., Business, 2021 Annual Report 102–7 Scale of the organization, including: • Total number of employees. • Total number of operations. • Net sales (for private sector organizations) or net revenues (for public sector organizations). • Total capitalization (for private sector organizations) broken down in terms of debt and equity. • Quantity of products or services provided. 2021 Annual Report Item 1., Business, 2021 Annual Report ESG Data Table – 2021 Year in Review 102–8 a. Total number of employees by employment contract (permanent and temporary), by gender. b. Total number of employees by employment contract (permanent and temporary), by region. c. Total number of employees by employment type (full-time and part-time), by gender. d. Whether a significant portion of the organization’s activities are performed by workers who are not employees. If applicable, a description of the nature and scale of work performed by workers who are not employees. e. Any significant variations in the numbers reported in Disclosures 102-8-a, 102-8-b and 102-8-c (such as seasonal variations in the tourism or agricultural industries). f. An explanation of how the data have been compiled, including any assumptions made. Item 1., Business, 2021 Annual Report ESG Data Table – 2021 Year in Review 102–9 A description of the organization’s supply chain, including its main elements as they relate to the organization’s activities, primary brands, products and services. Item 1., Business, 2021 Annual Report GRI Content Index Prepared in accordance with the most current standard, which can be found on www.globalreporting.org.