The Canadian company that played a major role in creating the once glitch-plagued Web site is working on a $4.5 million contract to help the Internal Revenue Service handle its responsibilities under the Affordable Care Act.

The IRS hired CGI Federal to help “integrate various work projects” related to the health-care law, according to a statement from the agency last week. The firm is one of more than 30 contractors that helped build the government’s $800 million online insurance exchange, which failed when it first launched in October 2013.

Rep. Peter Roskam (R-Ill.) issued a letter to IRS Commissioner John Koskinen on Friday demanding information about the agreement, including all internal communications regarding the decision. Roskam, who heads the House Ways and Means Subcommittee on Oversight, sent the request days after the Daily Caller reported the CGI contract in an article last week.

“Given your publicly-stated concerns about resource challenges at the IRS, I am seeking assurance that taxpayer dollars are being put to their highest and best use,” the lawmaker said.

The letter came one day after the Department of Health and Human Services inspector general issued a report saying HHS did not properly vet the contractors that built

The IRS said in a statement last week that it has worked with CGI Federal “going back several years” and that the contract was part of a multi-year award that started in 2011 and continued with a five-year agreement completed in August 2013, months before the failed launch of

The agency also said that its work on the Affordable Care Act “continues to go well” and that it “closely monitors all of our work involving the health-care initiative, including contractors.”

Under the contract, CGI Federal will not run or operate any part of, including the pages related to the Affordable Care Act, the agency said.

The government fired CGI Federal from the project in January 2014, opting to go with another firm to finish the company’s work. Agency officials decided that CGI had not been effective enough in fixing the computer system that serves as the underpinning of the online exchange, according to a Washington Post report at the time.

A firm hired to review CGI Federal’s performance with the exchange found 21,000 lines of defective software code in the system, according to a report last year from Republicans on the Senate Finance and Judiciary Committee.

The Centers for Medicare and Medicaid Services, a Department of Health and Human Services agency responsible for, has fixed the bugs in Web site, and more than 7 million Americans have enrolled in insurance plans through the portal. But the early problems added significant costs to the project.

CGI Federal also created online insurance exchanges for Massachusetts and Vermont, both of which terminated their contracts with the company last year after their sites failed to work.

CGI Federal spokeswoman Linda Odorisio said in a statement on Monday that the company has “established a strong record of service to the Department of Treasury and continues to take great pride in its work for the IRS.”

Roskam spokeswoman Stephanie Kittredge said Monday that the chairman “found the public response from the IRS unsatisfactory and intends to carefully review the actual contract, process, and communications that allowed the IRS to award a multi-million dollar contract to a company with a clear history of failing to produce results for taxpayers.”