The modern federal income tax was introduced in 1913, after passage of the Sixteenth Amendment to the Constitution. It is currently based on numerous factors, including filing status, number of dependents, and the gross earnings of each employee each year. During the history of this tax, the wage base on which percents have been computed has changed, as has the meaning of exemptions and deductions. The tables below give a rough guide to the history, but information is not always comparable from year to year.
| Highest Tax Bracket (from 1948, for married filing jointly) |
| Years | Rate | Floor | Comments
(Items not included in given rate) |
| 1913-1915 | 7% | $500,000 | |
| 1916 | 15% | $2,000,000 | |
| 1917 | 67% | $2,000,000 | |
| 1918 | 77% | $1,000,000 | |
| 1919-1921 | 73% | $1,000,000 | |
| 1922-1923 | 58% | $200,000 | In 1923, a statutory credit effectively reduced this rate to 43.5%. |
| 1924 | 46% | $500,000 | |
| 1925-1928 | 25% | $100,000 | |
| 1929 | 24% | $100,000 | |
| 1930-1931 | 25% | $100,000 | |
| 1932-1935 | 63% | $1,000,000 | |
| 1936-1940 | 79% | $5,000,000 | In 1940, a defense tax surcharge effectively increased this rate to 81.1%. |
| 1941 | 81% | $5,000,000 | |
| 1942-1943 | 88% | $200,000 | |
| 1944-1945 | 94% | $200,000 | The tax was limited to a 90% effective rate. |
| 1946-1947 | 91% | $200,000 | A statutory credit effectively reduced this rate to 86.45%. The tax was limited to a 90% effective rate (85.5% after credit). |
| 1948-1951 | 91% | $400,000 | In 1948-1949, statutory credits effectively reduced this rate to 82.13%, and in 1950, to 84.36%. The tax was limited to a 77% effective rate in 1948-1949, 87% in 1950, and 87.2% in 1951. |
| 1952-1953 | 92% | $400,000 | The tax was limited to an 88% effective rate. |
| 1954-1963 | 91% | $400,000 | The tax was limited to an 87% effective rate. |
| 1964 | 77% | $400,000 | |
| 1965-1976 | 70% | $200,000 | Vietnam War surcharges effectively increased this rate to 75.25% in 1968, 77% in 1969, and 71.75% in 1970. The tax was limited to a 60% effective rate in 1971, and 50% in 1972-1976. In 1974, a statutory rebate effectively reduced this rate. |
| 1977-1978 | 70% | $203,200 * | The tax was limited to an 50% effective rate. |
| 1979-1981 | 70% | $215,400 * | In 1981, a statutory credit effectively reduced the rate to 69.125%. The tax was limited to an 50% effective rate. |
| 1982 | 50% | $85,600 * | |
| 1983 | 50% | $109,400 * | |
| 1984-1986 | 50% | $162,400 + * | See the Indexing to Inflation table below. |
| 1987 | 38.5% | $90,000 | |
| 1988-1990 | 28% | $29,750 + | See the Indexing to Inflation table below. |
| 1991-1992 | 31% | $82,150 + | See the Indexing to Inflation table below. |
| 1993-2000 | 39.6% | $89,150 + | Floor statutorially adjusted to $250,000 in 1994. See the Indexing to Inflation table below. |
| 2001 | 39.1% | $297,350 | |
| 2002-2003 | 38.6% | $307,050 + | See the Indexing to Inflation table below. |
| 2004-2012 | 35% | $319,100 + | See the Indexing to Inflation table below. |
| 2013- | 39.6% | $450,000 + | See the Indexing to Inflation table below. |
