Figure 6 Sources of Medicare Revenue, 2014 1% General revenue 41% 38% Payroll taxes Premiums 73% 74% Transfers from states 87% Taxation of Social Security benefits Interest 15% 13% 25% Other 1% 1% 2% 7% 3% 1% 11% 1% 3% 1% 1% Part A Part B Part D $261.2 billion $259.8 billion $78.2 billion TOTAL $599.3 billion NOTE: Data are for the calendar year. SOURCE: 2015 Annual Report of the Boards of Trustees of the Federal Hospital Insurance and Federal Supplementary Medical Insurance Trust Funds. THE HENRY J. KAISER FAMILY FOUNDATION