Top 50% Pays 97% of All Federal Income Taxes
The U.S. income tax system is highly progressive. The top 1% of income earners, by household, paid more than 39% of all federal income taxes in 2005, the top 10% paid more than 70%, and the top 50% paid almost 97%, whereas the bottom 50% paid a little over 3%. Further, 32% of all tax returns filed in 2005 were from people who paid no federal income tax at all.
The chart below (click to enlarge) shows graphically the levels of household income earners, and their proportion of the federal income tax in 2005: