NBC News - For most Americans, the tax increases passed in January 2013 look like ancient history. But for the wealthy, the bill for those changes is now coming due.

The euphemistically named American Taxpayer Relief Act brought the top tax rate to 39.6 percent from 26 percent in 2012. (Whether you call this "reverting" or "raising" depends on your partisan bent). The change also phased out certain personal exemptions and it limited itemized deductions.

Taken all together, the "tax relief" for most Americans will hit the top earners when they pay their tax bills this month.

The top 1 percent of earners will pay an average tax bill of $525,231, up more than $36,000 from last year, according to the nonpartisan Tax Policy Center. It will surge to $670,000 for 2014 taxes.

The top 0.1 percent will see even bigger tax bills. That group will have an average tax burden of $2.6 million for 2013 taxes, up from $2.3 million in 2012.

The incomes of the top 1 percent are also going up, of course. The average income of the top 1 percent is expected to rise from $1.67 million in 2013 to just over $2 million in 2014.

But the average tax rate that top earners actually pay is also going up. The average tax rate for the top 1 percent will go from 27.2 percent for 2012 taxes to 31.4 percent for 2013 taxes, and 33.4 percent for 2014 taxes, according to the Tax Policy Center.

The top 5 percent of taxpayers now paid an estimated 27 percent of federal taxes in 2012 and their share will rise to 29.8 percent next year.