Income tax in the United States These treaties reduce the chance of double taxation by allowing each country to fully tax its citizens and residents and reducing the amount the other country can tax them. Generally the treaties provide for reduced rates of tax on investment income and limits as to which business income can be taxed. The treaties each define which taxpayers can benefit from the treaty. The United States social insurance system is funded by a tax similar to an income tax. Social Security tax of 6.2% is imposed on wages paid to employees. The tax is imposed on both the employer and the
Income tax in the United States applies to net investment income in excess of certain thresholds. An individual pays tax at a given bracket only for each dollar within that tax bracket's range. The top marginal rate does not apply in certain years to certain types of income. Significantly lower rates apply after 2003 to capital gains and qualifying dividends (see below). Income tax for year 2017: Single taxpayer making $40,000 gross income, no children, under 65 and not blind, taking standard deduction; Note, however, that taxpayers with taxable income of less than $100,000 must use IRS provided tax tables. Under that table for 2016, the