Federal Corporate Income Tax Rates, Income Years 1909-2018
The creation of the federal corporate income tax occurred in 1909, when the uniform rate was 1% for all business income above $5,000. Since then the rate has increased to as high as 52.8% in 1969. On Jan. 1, 2018 the corporate tax rate was changed from a decades-long tiered structure which staggered corporate tax rates based on company income to a flat rate of 21% for all companies.
(a) In addition to the rates shown, certain types of 'excess profits' levies were in effect in 1917-1921 and 1933-1945
(b) Less adjustments: 14.025% of dividends received and 2.5% of dividends paid.
(c) The Tax Reform Act of 1969 extended the Surcharge at a 5 percent rate from January 1, 1970 through June 1, 1970. On an annualized basis the Surcharge would be 2.5 percent.
(d) The Revenue Act of 1978 repealed the corporate normal tax and surtax and in their place imposed a graduated rate structure with five brackets.
(e) The Deficit Reduction Act of 1984 placed an additional 5 percent to the tax rate in order to phase
out the benefit of the lower graduated rates for corporations with taxable income between
$1,000,000 and 1,405,000. Corporations with taxable income above $1,405,000, in effect, pay a flat marginal rate of 46 percent.
(f) Rates shown effective for tax years beginning on or after July 1, 1987. Taxable income before
July 1, 1987 was subject to a two tax rate schedule or a blended tax rate.
(g) An additional 5 percent tax, not exceeding $11,750, is imposed on taxable income
between $100,000 and $335,000 in order to phase out the benefits of the lower graduated rates.
(h) An additional 3 percent tax, not exceeding $100,000, is imposed on taxable income between
$15,000,000 and $18,333,333 in order to phase out the benefits of the lower graduated rates.
Tax Foundation, "Federal Corporate Income Tax Rates, Income Years 1909-2012," taxfoundation.org, July 6, 2012
RSM, "2015 Federal Tax Rates," rsmus.com, Jan. 1, 2015
RSM, "2016 Federal Tax Rates," rsmus.com, Jan. 1, 2016
RSM, "2017 Federal Tax Rates," rsmus.com, Jan. 1, 2017
United States Congress, "H.R.1 - an Act to Provide for Reconciliation Pursuant to Titles II and V of the Concurrent Resolution on the Budget for Fiscal Year 2018," congress.gov (accessed Feb. 5, 2018)