Effective Tax Rate ($ in millions) Q4'15 Q1'16 Q2'16 Q3'16 Q4'16 Q1'17 Q2'17 Q3'17 Q4'17 Income before provision for income taxes $ 2,557 $ 2,066 $ 2,754 $ 3,164 $ 4,533 $ 3,408 $ 4,488 $ 5,236 $ 7,462 Provision for income taxes 995 328 471 537 965 344 594 529 3,194 Effective Tax Rate 39% 16% 17% 17% 21% 10% 13% 10% 43% In December 2017, the 2017 Tax Cuts and Jobs Act was enacted and significantly impacted the U.S. tax law. As a result of this legislation, our fourth quarter and full year 2017 provision for income taxes increased by $2.27 billion, which impacted our effective tax rate, net income and diluted earnings per share (EPS) for such periods. Our diluted EPS decreased by $0.77 for both the fourth quarter and full year 2017. 12