Based on a report of Distribution of Household Income and Federal Tax for 2010, Congressional Budget Office (CBO) pointed out that the share of taxes paid by higher-income households in the United States significantly exceeded their share of before-tax income

In 2010, households in the highest income tier received 51.9 percent of before-tax income and paid 68.8 percent of federal taxes; and households in the top 1 percent received 14.9 percent of before-tax income and paid 24.2 percent of federal taxes. Households in the base tier received 5.1 percent of income and paid 0.4 percent of taxes, and households in the middle tier received 14.2 percent of income and paid 9.1 percent of taxes.

In 2010, the lowest tier’s average income tax rate was -9.2 percent and the second income tier’s rate was -2.3 percent, due to the incidence of refundable tax credits. The top 1 percent of the population, on average, paid 20.1 percent of their income in individual income taxes in 2010.

In addition, The CBO also observed the overall effect of the tax rule changes between 2010 and 2013, and find out that average rates are projected to rise by 1.6 percent for households in the lowest tier, by 1.0 percent for those in the middle tier, and by 4.2 percent for the top percentile.