Hillary Clinton Expected to Release 2015 Tax Returns Running mate Tim Kaine will release his returns from the last 10 years.

 -- Hillary Clinton will release her 2015 tax returns in the coming days, possibly as soon as Friday, a source close to the Democratic presidential nominee told ABC News today.

Her running mate, Sen. Tim Kaine of Virginia, is expected to release his returns from the last 10 years, the source added.

The Clinton campaign has hammered opponent Donald Trump over his refusal to release his tax documents, and this move is likely to increase the pressure on him to do so.

"What about his taxes? We’ll get around to that too," Clinton told the crowd during a campaign stop in New Jersey in May. "Because when you run for president, especially when you become the nominee, that is kind of expected. So you gotta ask yourself, why doesn't he want to release them? Yeah, well, we’re going to find out."

Last year she and Bill Clinton released all their tax returns from 2007 to 2014.

In 2014, the most recent tax year available, the Clintons paid an effective federal tax rate of 35.7 percent.

From 2007 to 2014, the Clintons paid about $57 million in taxes. They made a total of $140,937,785 in those years, according to ABC News' calculations.