Congress wants answers on why the IRS targeted conservative groups, two senior politicians from both sides of the aisle told CNBC on Thursday.
Sen. Max Baucus, chairman of the Senate Finance Committee, said his hearings will "ask all the questions, get the facts, and let the facts determine our conclusions and where this goes to."
The Republican chairman of the House Ways and Means Committee, Rep. Dave Camp of Michigan, echoed those comments, telling CNBC that hearings with outgoing acting IRS Commissioner Steven Miller will focus on getting answers to why the agency targeted groups "for their political beliefs and how pervasive they were."
"We need to get answers," Camp said. "We've been trying to get this information for more than two years."
Baucus, a Montana Democrat, added that the hearings will be nonpartisan, with politicians of both parties looking for answers.
Also on CNBC, Rep. Charles Boustany, R-La., said he's confident congressional investigators will follow the "paper trail" to hold to account those responsible.
"The IRS is the most powerful organization, basically, in our federal government," said Boustany. "If a taxpayer is misleading or lies in their interactions with the IRS, there are severe penalties. It goes both ways. We're going to hold these individuals accountable."
(Read More: Stop 'Rot', Abuse at IRS: Rep. Boustany)
One of the potential positives of the IRS scandal is that it may push Congress toward reforming the U.S. tax code.
"This IRS scandal is an opportunity to look into the statutes that tend to create this scandal," Baucus said.
(Read More: Stop IRS Culture of 'Rot and Abuse': Rep. Boustany)
Baucus said he's looking at how to make the tax code more efficient and more competitive by removing its complexity.
Camp, who is pursuing tax reform in the House, said: "What we want to do is lower rates and do that by closing special interest Washington loopholes" in order to promote economic growth.
Camp is looking at revenue-neutral reform that doesn't raise or cut total government tax receipts. But while Baucus said "everything is on the table in tax reform," he wouldn't commit to revenue-neutral reform.
While the senator told CNBC he'd be willing to closing loopholes like the mortgage interest deduction, he wasn't ready to determine whether some of that tax revenue would go to deficit reduction as well as lowering tax rates for individuals. That he said was a later discussion.
But that doesn't preclude the possibility for meaningful reform. "The issue isn't 'are we going to have differences,' it's that we're committed to resolving those differences," Camp added.
Camp expects to have a bill by the end of the year.