Federal income tax rates have been modified frequently. Tax rates were changed in 34 of the 97 years between 1913 and 2010.See changes in 1916, 1917, 1918, 1921, 1922, 1924, 1926, 1928, 1932, 1934, 1935, 1936, 1940, 1941, 1942, 1943, 1944, 1945, 1948, 1950, 1951, 1953, 1954, 1964, 1968, 1969, 1975, 1978, 1981, 1986, 1993, 1997, 2001, and 2003. The rate structure has been graduated since the 1913 act.
Federal income tax rates have been modified frequently. Tax rates were changed in 34 of the 97 years between 1913 and 2010.See changes in 1916, 1917, 1918, 1921, 1922, 1924, 1926, 1928, 1932, 1934, 1935, 1936, 1940, 1941, 1942, 1943, 1944 1945, 1948, 1950, 1951, 1953, 1954, 1964, 1968, 1969, 1975, 1978, 1981, 1986, 1993, 1997, 2001, and 2003. The rate structure has been graduated since the 1913 act.