out at higher income levels. The U.S. federal and most state income tax systems tax the worldwide income of citizens and residents. A federal foreign tax credit is granted for foreign income taxes. Individuals residing abroad may also claim the foreign earned income exclusion. Individuals may be a citizen or resident of the United States but not a resident of a state. Many states grant a similar credit for taxes paid to other states. These credits are generally limited to the amount of tax on income from foreign (or other state) sources. Filing status Federal and state income tax is calculated, and returns filed, for each taxpayer. Two married individuals may calculate tax and file returns jointly or separately. In addition, unmarried individuals supporting children or certain other relatives may file a return as a head of household. Parent-subsidiary groups of companies may elect to file a consolidated return. There are currently five filing statuses for filing federal individual income taxes: single, married filing jointly, married filing separately, head of household, and qualifying widow(er). The filing status used is important for determining which deductions and credits the taxpayer qualifies for. States may have different rules for determining a taxpayer's filing status, especially for people in a domestic partnership. Graduated tax rates Income tax rates differ at the federal and state levels for corporations and individuals. Federal and many state income tax rates are higher (graduated) at higher levels of income. In addition, federal and many state individual income tax rate schedules differ based on the individual's filing status. For example, the income level at which each rate starts generally is higher (i.e., tax is lower) for married couples filing a joint return or single individuals filing as head of household. Individuals are subject to federal graduated tax rates from 10% to 37%. Corporations are subject to a 21% federal rate of tax. Prior to 2018, the effective date of the Tax Cuts and Jobs Act of 2017, corporations were subject to federal graduated rates of tax from 15% to 35%; a rate of 34% applied to income from $335,000 to $15,000,000. State income tax rates, in states which have a tax on personal incomes, vary from 1% to 16%, including local income tax where applicable. Nine states do not have a tax on ordinary personal incomes. These include Alaska, Florida, Nevada, South Dakota, Texas, Washington, and Wyoming. State and local