Center on Budget and Policy Priorities, Misconceptions and Realities About Who Pays Taxes:

Close to half of U.S. households currently do not owe federal income tax. The Urban Institute-Brookings Tax Policy Center estimates that 46% of households will owe no federal income tax for 2011. A widely cited figure is a Joint Committee on Taxation estimate that 51% of households paid no federal income tax in 2009. (The TPC figure for 2009 also is 51%.)

These figures are sometimes cited as evidence that low- and moderate-income families do not pay sufficient taxes. Yet these figures, their significance, and their policy implications are widely misunderstood.