Citizens for Tax Justice, Who Pays Taxes in America?:

It’s often claimed that the richest Americans pay a disproportionate share of taxes while those in the bottom half pay nothing. These claims ignore the many taxes that most Americans are subject to — federal payroll taxes, federal excise taxes, state and local taxes — and focus instead on just one tax, the federal personal income tax. The other taxes are mostly regressive, meaning they take a larger share of income from a poor or middle-income family than they take from a rich family.

Many Americans do not have enough income to owe federal personal income taxes, but do pay these other taxes. The federal personal income tax is a progressive tax, and the combination of this tax with the other (mostly regressive) taxes results in a tax system that is, overall, just barely progressive. Total tax obligations are, on average, fairly proportional to income.

This table illustrates the share of total taxes (all federal, state and local taxes) paid by Americans in different income groups in 2011.