Taxation in the United States is progressive, and is levied at the federal, state, and local government levels. This includes taxes on income, payroll, property, sales, imports, estates, and gifts, as well as various fees. Taxation in the United States is based on citizenship, not residency. Both non-resident citizens and Green Card holders living abroad are taxed on their income irrespective of where they live or where their income is earned. The United States is one of the few countries in the world to do so.