Income tax in the United States Income tax in the United States Income taxes in the United States are imposed by the federal, most state, and many local governments. The income taxes are determined by applying a tax rate, which may increase as income increases, to taxable income, which is the total income less allowable deductions. Income is broadly defined. Individuals and corporations are directly taxable, and estates and trusts may be taxable on undistributed income. Partnerships are not taxed, but their partners are taxed on their shares of partnership income. Residents and citizens are taxed on worldwide income, while nonresidents are taxed only on income
Legal history of income tax in the United States (1916), the 1913 Act was ruled to be constitutional. A separate excise tax was also imposed on corporations. Subsequent legal actions were concerned with what should be counted as "income" under the 1913 Act. In "Eisner v. Macomber" (1920), the Supreme Court ruled that proportionate stock dividends were not taxable as income, on the grounds that the dividend income was not "severable" from the capital holding from which it was derived. Later decisions, however, have tended to limit this view of "severability," and to uphold the federal statutes as exertions of the power of Congress to tax. The first attempt