Social Security's Old-Age, Survivors, and Disability Insurance (OASDI) program and Medicare's Hospital Insurance (HI) program are financed primarily by employment taxes. Tax rates are set by law (see sections 1401, 3101, and 3111 of the Internal Revenue Code) and apply to earnings up to a maximum amount for OASDI.

The rates shown reflect the amounts received by the trust funds. In certain years, the effective rate paid by employees, employers, and/or self-employed workers was less than the rate received by the trust funds, with the difference covered by general revenue. See the footnotes for details.

Calendar year Tax rates as a percent of taxable earnings
Rate for employees and employers, each Rate for self-employed workers
OASDI HI Total OASDI HI Total
1937-49 1.000 -- 1.000 -- -- --
1950 1.500 -- 1.500 -- -- --
1951-53 1.500 -- 1.500 2.250 -- 2.250
1954-56 2.000 -- 2.000 3.000 -- 3.000
1957-58 2.250 -- 2.250 3.375 -- 3.375
1959 2.500 -- 2.500 3.750 -- 3.750
1960-61 3.000 -- 3.000 4.500 -- 4.500
1962 3.125 -- 3.125 4.700 -- 4.700
1963-65 3.625 -- 3.625 5.400 -- 5.400
1966 3.850 0.350 4.200 5.800 0.350 6.150
1967 3.900 0.500 4.400 5.900 0.500 6.400
1968 3.800 0.600 4.400 5.800 0.600 6.400
1969-70 4.200 0.600 4.800 6.300 0.600 6.900
1971-72 4.600 0.600 5.200 6.900 0.600 7.500
1973 4.850 1.000 5.850 7.000 1.000 8.000
1974-77 4.950 0.900 5.850 7.000 0.900 7.900
1978 5.050 1.000 6.050 7.100 1.000 8.100
1979-80 5.080 1.050 6.130 7.050 1.050 8.100
1981 5.350 1.300 6.650 8.000 1.300 9.300
1982-83 5.400 1.300 6.700 8.050 1.300 9.350
1984 a 5.700 1.300 7.000 11.400 2.600 14.000
1985 a 5.700 1.350 7.050 11.400 2.700 14.100
1986-87 a 5.700 1.450 7.150 11.400 2.900 14.300
1988-89 a 6.060 1.450 7.510 12.120 2.900 15.020
1990 and later b, c 6.200 1.450 7.650 12.400 2.900 15.300
a In 1984 only, an immediate credit of 0.3 percent of taxable wages was allowed against the OASDI taxes paid by employees, resulting in an effective employee tax rate of 5.4 percent. The OASI and DI trust funds, however, received general revenue equivalent to 0.3 percent of taxable wages for 1984. Similar credits of 2.7 percent, 2.3 percent, and 2.0 percent were allowed against the combined OASDI and HI taxes on net earnings from self-employment in 1984, 1985, and 1986-89, respectively.
b Beginning in 1990, self-employed workers are allowed a deduction, for purposes of computing their net earnings, equal to half of the combined OASDI and HI contributions that would be payable without regard to the contribution and benefit base. The OASDI contribution rate is then applied to net earnings after this deduction, but subject to the OASDI base.
c For 2010, most employers were exempt from paying the employer share of OASDI tax on wages paid to certain qualified individuals hired after February 3. For 2011 and 2012, the OASDI tax rate is reduced by 2 percentage points for employees and for self-employed workers, resulting in a 4.2 percent effective tax rate for employees and a 10.4 percent effective tax rate for self-employed workers. These reductions in tax revenue due to lower tax rates will be made up by transfers from the general fund of the Treasury to the OASI and DI trust funds. Beginning in 2013, an additional HI tax of 0.9 percent is assessed on earned income exceeding $200,000 for individuals and $250,000 for married couples filing jointly. This additional HI tax rate is not reflected in the tax rates shown in the table.