President Barack Obama's health secretary publicly apologized Wednesday for the rocky rollout of the US health care law's new website, stressing that citizens "deserve better" from the system. But while Secretary of Health and Human Services Kathleen Sebelius regretted that navigating HealthCare.gov has been a "miserably frustrating experience" for many, she insisted that so-called Obamacare has been working well for millions of Americans. For his part, Obama traveled to Massachusetts to defend his signature reforms in the state where in 2006 his former Republican presidential rival Mitt Romney adopted a system similar to the Affordable Care Act. "Today, 97 percent of Massachusetts residents have health insurance coverage and the primary attacks against this law -? many of which we are hearing again today about the ACA ?- never proved true," a White House official said. Josh Earnest, a White House spokesman, told reporters aboard Air Force One that "obviously governor Romney's efforts to work in bipartisan fashion to pass health care reform in Massachusetts will be the subject of the president's comments today." Sebelius, the point woman for the new health care law, sounded chastened about the trouble-plagued online portal through which millions are expected to register for health insurance. "Let me say directly to these Americans: You deserve better. I apologize. I'm accountable to you for fixing these problems," Sebelius, the seniormost administration official to testify before Congress on the law, told a closely-watched panel in the House of Representatives. And when Republican Congresswoman Marsha Blackburn grilled her and suggested she was seeking to pawn off responsibility on contractors like Verizon, Sebelius interrupted to say she herself would take the heat. "Hold me accountable for the debacle. I'm responsible," she said. HealthCare.gov, which allows access to exchange marketplaces where Americans can purchase private insurance, debuted on October 1. Committee Chairman Fred Upton said he has seen little improvement in the website's performance since then, noting that his staff was "hit with an error message" even as they tried to use the page early Wednesday. "Sadly here we are now five weeks into enrollment and the news seems to get worse by the day," Upton said. "After more than three years to prepare, malfunctions have become the norm." Sebelius' appearance came at the third hearing in a week addressing the faulty start to Obamacare. Critics like Blackburn have focused on how the law is booting millions of people off their plans, years after Obama told Americans that, if they liked their coverage, they could keep it. Sebelius countered that insurance companies routinely alter coverage in the individual market, and that people on these plans often hold them for less than a year. And skeleton policies that do not measure up to Obamacare's rules, including not providing free mammograms or charging women 50 percent more than men, will need to be changed to conform to the law. "If someone is buying a brand new policy... they will have consumer protections for the first time," Sebelius said. With Republicans seizing on the policy cancellations letters, Sebelius pushed back, saying it was insurance companies altering their inadequate plans in order to conform with Obamacare. "This market has always been the Wild West," she said of the individual marketplace, in which some five percent of Americans buy health coverage. Republican Joe Barton took a swipe at Sebelius, a former Kansas governor, by suggesting she might be in over her head. "We're not in Kansas anymore," Barton sneered. "Some might say that we are actually in 'Wizard of Oz' land given the parallel universes we appear to be habitating." But Democrats like Henry Waxman rode to Sebelius's rescue. "I would urge my colleagues to stop hyperventilating," he said. "The early glitches in this rollout will soon be forgotten... and then every American will finally have access to affordable health insurance." Last week, the lead contractors, which collectively have been paid hundreds of millions of dollars to create and manage the website, said there was insufficient testing of the online portal. Asked if the two weeks of end-to-end testing was enough, Sebelius replied "clearly not." As critics pounced on the website's shortcomings, Democrat Eliot Engel noted the irony of Republicans who abhored the premise of Obamacare yet were making a "big show" about how Americans cannot get access to the health care options fast enough. "You're really on the wrong side of history here," Engel told Republicans. In defending the site, Sebelius at one point said "the website has never crashed" although it has been slow. That prompted rapid-fire reaction by House Speaker John Boehner, who tweeted a Wednesday photo showing HealthCare.gov, bearing the message: "The system is down at the moment."