Sebelius testified as another controversy brewed over a wave of cancellation notices hitting small businesses and individuals who buy their own insurance. Republicans say that contradicts one of Obama's earliest promises about the health law: You can keep your plan if you like it. Obama's promise dates back to June 2009, when Congress was starting to grapple with how to cover millions of uninsured Americans.
The cancellations affect some of the 5 percent of Americans who buy health insurance on the private market rather than the overwhelming majority who have coverage through their employer or through the government Medicare program for people at age 65.
Further putting the administration on the defensive, a major contractor involved in building the website told the government last month it didn't have enough time to test its product.
CGI Federal also told the Centers for Medicare and Medicaid Services in a memo that it could not get access to computer logs that would have pinpointed potential problems. The contractor labeled that issue as "severe" as recently as June, and said a compressed schedule for opening the site on Oct. 1 did not allow enough time for adequate testing.
The House Committee on Oversight and Government Reform asked CGI Federal for the documents last week. It released them to the public late Tuesday.
As Sebelius testified before the House Energy and Commerce Committee, growing number of Republicans in Congress are calling for her to step down or be fired.
Obama was traveling to Boston where planned to speak about the embattled law Wednesday from Boston's historic Faneuil Hall, where Massachusetts Republican Gov. Mitt Romney was joined by the late Democratic Sen. Ted Kennedy to sign the state's 2006 healthcare overhaul bill, a model for Obamacare. Obama was pointing to the bipartisan effort to get the program launched in Massachusetts to encourage his opponents to stop rooting for his law's failure.
The White House said Obama planned to point out Massachusetts' sluggish start Wednesday. Jonathan Gruber, a Massachusetts Institute of Technology economics professor who advised both Romney and Obama on the development of their laws, said only 123 paying consumers signed up the first month of the Massachusetts law, with 36,000 coming on by the time penalties kicked in for failing to have insurance.
While more people did sign up as the deadline approached in Massachusetts, its law never faced high-profile computer woes or such fierce opposition. Even though the federal law was modeled on Romney's, the former governor ran for president against Obama last year on a campaign to repeal the federal version.
While the law doesn't create a government-run system like Britain's, it does mandate that large employers provide insurance and that everyone must be insured or face tax penalties. Those who can't afford insurance can receive subsidies in states that accepted federal money for an expansion of the Medicaid program for low-income Americans. Several Republican-governed states rejected the federal money and are not expanding Medicaid.
On Tuesday, Medicaid chief Marilyn Tavenner was questioned for nearly three hours by members of the House Ways and Means Committee. The hearing quickly devolved into a resumption of Republican arguments against the whole program. House Republicans have tried to revoke or delay the new healthcare law at least 40 times since it was signed into law in 2010. Most recently, Republicans demanded that Obama gut the program in exchange for ending a partial government shutdown this month and avoiding a debt default. That effort collapsed in a fury of voter disapproval of the tactic.
At Tuesday's hearing, Republicans wanted to know why so many of their constituents were getting cancellation notices from their insurance companies.
As early as last spring, state insurance commissioners started giving insurers the option of canceling existing individual plans for 2014, because the coverage required under Obama's law is significantly more robust. Some states directed insurers to issue cancellations. Large employer plans that cover most workers and their families are unlikely to be affected.
Tavenner blamed insurance companies for cancelling the policies and said most people who lose coverage will be able to find better replacement plans in the health insurance exchanges, in some cases for less money. Change is a constant in the individual insurance market, she said. Telling Congress about half of plans "churn" over in any given year.
Tavenner delivered the most direct mea culpa yet from the administration for the technical problems that have kept many Americans from signing up through HealthCare.gov. Consumers complain that the site is slow, locks up and often kicks them off before they can complete their application.
"I want to apologize to you that the website has not worked as well as it should," she told the Ways and Means Committee.