WASHINGTON – The top 0.01 percent of Americans — fewer than 14,000 households — received 5.6 percent of adjusted gross income in 2012, according to data released Wednesday by the IRS.

That was the biggest share of income concentrated at the very top of the distribution scale since 2007. Those in that group had a minimum income of $12.1 million.

An even more exclusive group — the top 0.001 percent — also had its best year since 2007. Their average tax rate was 17.6 percent, which is lower than the average rate for the top 10 percent of the U.S. population.

That year — 2012 — was unusual for high earners, because it was the end of the 15 percent top rate on capital gains and dividends. The increase to 23.8 percent on Jan. 1, 2013, prompted many high earners to sell their appreciated assets before the deadline and take advantage of lower rates.

The Internal Revenue Service report also shows how the U.S. tax system remains broadly progressive — meaning those with higher incomes pay higher tax rates. The top 3 percent of households, who received 30.9 percent of adjusted gross income, paid more than half of individual income taxes. And that was before tax increases for top earners took effect in 2013.

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