Lawmakers on Capitol Hill are clashing over privacy concerns as a major part of Obamacare is set to take effect in two months.
Health insurance exchanges are set to start running Oct. 1. The application process requires the Internal Revenue Service to share private data with other agencies working to enroll people in the program.
That has sparked concerns about protecting privacy, especially after the way IRS officials targeted conservative groups before last year's election.
"This data hub is a hacker's dream, but I don't know who I most fear; someone from the outside hacking the information or the way our government handles it," Rep. Sam Johnson, R-Texas, said.
"Why should we trust the IRS to trust our taxpayer information under Obamacare?" he asked.
"We share information roughly with 300 different federal and state agencies as a matter of routine, and we have procedures and safeguards in place to protect that information," Daniel Werfel, IRS deputy commissioner, said.
Democrats argued that the Obamacare hearings are politically motivated.
Meanwhile, Republicans said the IRS-Tea Party scandal was real, and they're worried about the IRS overseeing the Affordable Care Act.
"This hearing is really the culmination of months of a careful buildup. The majority has been crafting a scandal narrative to support their truly relentless agenda to repeal the ACA," Rep. Jim McDermott, D-Va., said.
"No matter what our colleagues try to say to whisk this issue away, the government was intimidating people and targeting them based upon their political views; that's not phony. That's real," Rep. Paul Ryan, R-Wis, said.
The hearings come before what's expected to be the 40th House vote to repeal Obamacare.