An issue involving coverage of Capitol Hill staff members under the Affordable Care Act resulted in the ranking Republican on a Senate oversight committee saying Wednesday that he would put a hold on the nominee for federal personnel director.

Sen. Tom Coburn (R-Okla.) said he would delay a full Senate confirmation vote on Office of Personnel Management nominee Katherine Archuleta pending answers from the administration regarding health insurance coverage for Capitol Hill staffers once the ACA kicks in. The Homeland Security and Governmental Affairs Committee approved her on a partisan vote.

Under the law, also known as Obamacare, members of Congress and at least some congressional staffers will have to leave the Federal Employees Health Benefits Program and get their health coverage under the ACA’s insurance marketplaces, or exchanges, starting in January.

That provision, sponsored by Sen. Charles Grassley (R-Iowa), reflected pressures during the law’s consideration that political leaders should personally have the same health care as members of the public who will be getting their coverage through the ACA.

However, the law didn’t create procedures for the exchanges to handle premium contributions for large employers, and it’s not clear that the federal government has the authority to pay for congressional staffers on the exchanges, the way it pays for them now.

Like other enrollees in the FEHBP, members of Congress and their staff receive an employer contribution toward premiums in that program that covers about 70 percent of the total cost. However, there has been an unresolved question since the law passed in early 2010 whether that contribution would continue for those persons once they leave the FEHBP. There also is some uncertainty whether the requirement to leave that program applies to all employees of Congress or just to those on a member’s personal staff.

The situation has caused growing anxiety among congressional staffers as the startup of the ACA approaches, raising the prospect that retirement-eligible Hill employees would choose to retire before the end of this year in order to keep their health coverage as retirees under the current terms.

On Capitol Hill, “chiefs of staff are concerned about a brain drain, that senior staff have a significant incentive to leave now,” said Bradford Fitch, president and CEO of the Congressional Management Foundation, a nonpartisan organization that works with Congress to improve its operations.

“It’s not just an issue of forcing federal employees out of FEHBP, it’s the uncertainty of whether their employer will continue to contribute to their health-care plan. They don’t know anything and they‘re getting very worried,” he said, adding that those not eligible to retire might leave for private sector jobs that provide health care with an employer share.

Coburn, the committee’s top Republican, said “there’s no reason we should vote on this nomination until we know what the administration’s position is for our employees’ health insurance. I plan on holding that nomination until we get an answer, so that we can either legislate or do something for the very valuable staff that we have.

He denounced “the stupidity we have in the present law, a gutting of our own staff because someone was trying to make a political point.”

Spokespersons for the OPM and the Office of Management and Budget did not immediately respond to a request for comment.

During a brief discussion before the vote, several Democratic members spoke in favor of Archuleta, noting that during her confirmation hearing, she promised to tackle several long-running issues, including delays in processing of employee retirement applications. They also cited her experience in senior positions at the Labor, Energy and Transportation departments as well as with the city of Denver, among other jobs.

The OPM directorship “is largely a thankless task. The fact that she wants to take the position speaks volumes,” said Sen. Jon Tester (D-Mont.).  “I look forward to getting her on the job. Hopefully [Sen. Coburn] will get the information very soon and we can move forward on the nomination.”

Congress is set to take a five-week recess after this week.

Other enrollees in FEHBP, including executive branch employees and retirees, will not be required to leave the program.

OPM officials have said that the ACA allows those other FEHBP enrollees to voluntarily get their health-insurance coverage through the exchanges but that there would be a disincentive against doing so, since they would lose the employer contribution toward premiums.