Published: Oct 29, 2013 12:20 PM EDT

Happening Tuesday, lawmakers are getting a chance to grill a member of the Obama Administration over the rollout of the Affordable Care Act.

The Medicare chief is answering questions on what went wrong with the health care website and if things will really run smoothly by the end of November.

Marilyn Tavanner heads Medicare and Medicaid services, the agency in charge of the troubled healthcare dot gov website.

Lawmakers were quick to offer their opinions of her performance and wanted to know why the site was down in the first place.

Troubles with the site have many republicans and even some democrats pushing president obama to delay parts of his plan.

Tavanner is a former nurse and hospital administrator and says progress has been made and the site will be fixed.

"In the first few days when the site went live few could create an account, now 90 percent can," Tavenner says.

"You and your staff made claims to the American public and to Congress that everything would be ready on time, everything was a go.  None of that proved to be true," says Republican Texas Rep. Kevin Brady.

On Wednesday, a Congressional committee will question the Chief of Health and Human Services.  Many republicans are calling for her to resign in the wake of the troubled health care roll out.