Cheryl Campbell, senior vice president at CGI Federal, during a hearing on implementation of the Affordable Care Act before the House Energy and Commerce Committee on Thursday. Douglas Graham/CQ Roll Call/Getty Images

When can consumers expect the bug-ridden HealthCare.gov website to work?

That was one of the many questions left unanswered after a five-hour hearing in front of the House Energy and Commerce Committee focusing on the troubled rollout of the state-level online insurance exchanges for the Affordable Care Act (ACA).

The exchange portals were intended to be an easy one-stop shop for consumers to compare premiums, apply for federal subsidies and enroll in insurance plans. Instead, the site has been plagued with persistent problems as millions have tried and failed to apply for new coverage plans.

But the witnesses at the hearing — representatives from the four main contractors that worked on the website — provided little insight into exactly what went wrong and how long the problems will remain.

“I would not like to make a guess as to when it will be fixed because I don’t like to raise expectations,” said Cheryl Campbell, senior vice president at CGI Federal, the contractor that built the federal exchange website for 36 states. She previously expressed confidence that uninsured Americans shopping for coverage would be able to enroll by Jan. 1.

Rep. Gene Green, D-Texas, suggested adding parking spaces in front of the Rayburn building, where the hearing took place, implying that the witnesses would continue to be called before the committee until lawmakers get more answers. All the witnesses insisted that the components of the ACA website with which they were specifically tasked were working as planned and were quickly improving. But they admitted the system broke down when integrated.

The contractors laid the blame for that squarely at the feet of the Centers for Medicare and Medicaid Services (CMS), which they said was responsible for “end to end” testing and made the final decision to go live with the site on Oct. 1.

“If there was a silver bullet to answer that question, I would give it to you,” Campbell said when asked by Rep. Joe Pitts, R-Pa., why the website does not function properly. “It’s the end-to-end aspect that is a challenge.”

More details about implementation problems were unearthed during the hearing. The contractors said the system was not tested until just weeks before the site was set to go live.