Contributions to the Social Security and Medicare Trust Funds, by program and source, 2012-2021
(in millions of dollars)

Contributions to the Social Security and Medicare Trust Funds,
by program and source, 2012-2021
(in millions of dollars)
Program and source 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021
Social Security Trust Funds
Old-Age and Survivors Insurance a $628,302 $645,678 $674,584 $710,334 $710,497 $742,399 $750,371 $839,992 $895,014 $875,387
Employer 285,328 294,995 305,279 322,395 322,652 336,293 340,901 384,005 408,227 398,575
Employee 191,028 292,241 302,850 319,939 319,940 333,542 338,475 381,121 404,962 395,425
Self-employed 27,538 33,578 38,104 37,169 36,195 36,670 36,489 39,966 42,791 44,235
General Fund Reimbursement 97,735 4,169 395 278 87 17 18 11 3 1
Taxation of benefits 26,675 20,694 27,957 30,554 31,623 35,877 34,488 34,890 39,032 37,151
Disability Insurance a 102,744 106,523 111,488 116,508 158,600 169,063 169,719 140,961 146,997 142,826
Employer 48,451 50,095 51,840 54,747 75,347 79,498 80,576 65,906 69,299 67,677
Employee 32,487 49,603 51,427 54,330 74,887 78,854 79,992 65,222 68,747 67,143
Self-employed 4,677 5,704 6,470 6,312 7,157 8,734 8,617 8,249 7,247 7,547
General Fund Reimbursement 16,546 729 71 47 15 3 3 2 b b
Taxation of benefits 583 391 1,680 1,071 1,194 1,973 530 1,583 1,704 459
Medicare Trust Funds
Hospital Insurance a 227,814 238,544 248,762 264,489 279,821 289,164 296,082 312,799 319,017 337,164
Employer 95,618 102,318 104,720 112,027 118,309 121,488 125,025 132,889 141,590 140,885
Employee 95,618 102,318 104,720 112,027 118,309 121,488 125,025 132,889 141,590 140,885
Self-employed 14,494 16,182 18,006 17,020 16,899 18,520 18,232 19,359 20,108 20,773
Voluntarily enrolledc 3,441 3,417 3,251 3,206 3,282 3,463 3,608 3,880 4,034 4,181
Taxation of benefits 18,643 14,310 18,066 20,208 23,022 24,206 24,192 23,781 11,695 30,441
Supplementary Medical Insurancea, d 58,024 63,085 65,644 69,446 72,055 81,522 93,312 99,413 111,200 166,626
Aged 48,495 52,814 55,164 58,593 60,618 69,009 80,041 86,101 97,120 145,994
Disabled 9,529 10,270 10,479 10,852 11,438 12,513 13,271 13,312 14,081 20,632
a Totals do not necessarily equal the sum of rounded components. Employment taxes depend on tax rates, and, for the Old-Age and Survivors Insurance and Disability Insurance Trust Funds, wage bases (taxable maximums). (Beginning in 1994, no wage base applies to Medicare's Hospital Insurance program.) Employer and employee contributions differ by estimated amounts of employee tax overpayments and by employee tax on tips.
b Between -$500,000 and $500,000.
c Beginning in July 1973, aged ineligibles may voluntarily enroll for Hospital Insurance.
d Includes premiums paid on behalf of eligibles by State governments under "buy-in" arrangements.