The head of the Centers for Medicare & Medicaid Services on Tuesday apologized for the problem-plagued rollout of the federal website for Obamacare's public health exchanges.

“I want to apologize to you that the website has not worked as well as it should,” CMS Administrator Marilyn Tavenner told the public during a House Ways and Means Committee hearing focused on the Affordable Care Act.

“This website has not lived up to our expectations or the expectations of the American people," she added.

Tavenner's testimony came as the Obama administration attempts to convince the public that the website will be largely fixed by the end of November and that the cost of insurance won't skyrocket under the health care law.

CMS was responsible for making sure, which will enroll consumers in new insurance exchanges, was ready for launch on Oct. 1. The White House has since brought on former Office of Management and Budget Director Jeff Zients to lead efforts to fix the website.

Though Republicans seemed more focused on criticizing Health and Human Services Secretary Kathleen Sebelius, they dismissed Tavenner's explanations for the litany of early glitches.

“This was supposed to be the easy part,” Rep. Kevin Brady, R-Texas, said of constructing the website.

And of Tavenner’s claims that the website’s issues would be corrected by the end of next month, Brady asked, “Why should the American people believe you now?”

In the botched rollout, Republicans see a chance to cement charges they have been making for years: that Obamacare is an unworkable law not ready for primetime.

Democrats counter that Republicans are being disingenuous, that they can’t complain about a law they’ve actively tried for years to dismantle.

“We start this hearing facing a basic reality: Democrats want to make the Affordable Care Act work. Congressional Republicans don’t,” Rep. Sander Levin, D-Mich., said.

However, the administration has also taken flack for not providing Obamacare enrollment figures — they will release the first batch in mid-November — nor saying how many of the 700,000 people filling out applications will be covered by Medicaid rather than public exchanges.

“We expect the initial number to be small," Tavenner said, declining to give specific enrollment figures.

She pointed out that enrollment in the Massachusetts health program, which is the model for Obamacare, remained low during the first few months.

Administration officials say they expect enrollment numbers to grow closer to the individual mandate deadline, after which those without insurance will need to pay a fine.