[20190110]IN11015_联邦所得税：边际所得税税率如何运作？.pdf

CRS INSIGHT Prepared for Members and Committees of Congress INSIGHTINSIGHTi i The Federal Income Tax: How Do Marginal Income Tax Rates Work? Margot L. Crandall-Hollick Specialist in Public Finance January 10, 2019 Calculating Income Tax Liability For many taxpayers, calculating their federal income tax liability can be broken down into three main steps. 1. Taxpayers calculate the amount of their income subject to taxation (i.e., their taxable income). 2. Taxpayers apply marginal income tax rates to their taxable income to determine their “pre-tax credit” income tax liability. 3. Taxpayers subtract any tax credits from their pre-tax credit income tax liability to determine their final income tax liability. Some taxpayers with more complex tax situations, including those who are subject to the alternative minimum tax (AMT) and those who have income from capital gains and dividends, will have to perform additional steps to calculate their income tax liability. (Those cases are not discussed in this Insight.) For a visualization of this calculation, see CRS Infographic IG10011, The U.S. Individual Income Tax System, 2018, by Molly F. Sherlock. Applying Marginal Income Tax Rates This In