Department of Health and Human Services Secretary Kathleen Sebelius. (Lynne Sladky/AP)

Health and Human Services Secretary Kathleen Sebelius said Wednesday that the ailing health insurance Web site was improving thanks to “relentless” efforts to work out the bugs, and cited an uptick in enrollment as evidence that the program is back on track after a false start.

But she told a congressional panel that the problems that initially plagued were “unacceptable,” and that as a result she was creating a new position in the department to head off similar failures and had directed the HHS inspector general to investigate what went wrong.

“The initial launch of was flawed, frustrating and unacceptable,” Sebelius told members of the House Energy and Commerce Committee. “Now that the Web site is working more smoothly, I’ve determined it’s the right time to begin a process of better understanding the structural and managerial policies that led to the flawed launch so we can take action to avoid these problems in the future.”

About 365,000 Americans chose health plans during the first two months of the federal and state insurance marketplaces, administration officials announced Wednesday, bringing the total to more than triple the meager enrollment from October.

A report accompanying the announcement showed that the number of people who collectively signed up for coverage in the 14 states running their own insurance exchanges continued to outpace the total enrollment from the three dozen states relying on the federal marketplace.

During the hearing, Sebelius disclosed that through the end of October, the administration had spent $319 million on information technology related to — up from the $174 million figure she cited during her last appearance before the committee Oct. 30.

Asked by Rep. Fred Upton (R-Mich.), chairman of the committee, if she would have delayed the Oct. 1 launch date for, Sebelius responded, “On balance, I am not sure what the right answer is.”

“I would have done a slower launch, maybe with fewer people and perhaps more beta testing,” she said a little bit later.

Republicans also hammered on a theme that they have centered on in recent weeks as the administration has labored to repair the Web site — that the problems with the health-care law extend far beyond the technological issues. They cited the millions of Americans whose health plans are being cancelled despite assurances from President Obama that people who liked their insurance could keep it under his law.

“Millions of Americans are being harmed by this law,” Health subcommittee Chairman Joe Pitts (R-Pa.) said. “My constituents do not trust the administration when it comes to the Affordable Care Act, and it is they who are suffering because of these broken promises.

But the uptick in enrollment provided fodder for Democratic lawmakers, who have struggled to defend the law’s poor rollout this fall but contended on Wednesday that the health law’s benefits were finally coming into focus now that the Web site is functioning better.

“We’re beginning to hear the stories of people finally getting the security and peace of mind that comes with quality health insurance,” Rep. Henry Waxman (D-Calif.) said. “And some of these stories are very powerful.”

In a blog post published Wednesday morning before the hearing, Sebelius said she has asked HHS Inspector General Dan Levinson, to review the development of the Web site with a particular focus on the Centers for Medicare and Medicaid Services, the agency known as CMS that oversaw the creation of the Web site, and the private firms that were contracted to work on the project.

She also announced the creation of a “chief risk officer” within CMS, who will report to the agency’s administrator, Marilyn Tavenner. The officer’s first task will be to review acquisition and contracting related to information technology.

The review is the latest sign that the Obama administration has moved into a new phase in its effort to manage fallout from the broken Web site, which stumbled out of the gate Oct. 1, suffering frequent crashes and other technical bugs. After meeting its self-imposed deadline to fix the site for most users by Dec. 1, the administration is now embarking on an effort to repair trust in the program.

Sebelius’s announcement follows news last week that the White House was bringing back a former aide, Phil Schiliro, to help oversee its health policy efforts.

The measures announced by Sebelius on Wednesday constitute “initial steps” of a broader accountability effort and will center largely on contracting and the Medicare agency. Administration officials have repeatedly blamed the main contractor on the project, CGI Federal, for many of the lapses. The firm has said it did the job it was hired to do and faulted the Medicare agency, which had ultimate responsibility for managing and testing the overall project.

In the wake of the problems, the administration hired a different firm, Quality Software Services Inc., to serve as general contractor in charge of the project and brought in Jeffrey Zients, a former acting head of the Office of Budget and Management, to oversee the fixes.

HHS is the third-largest federal contracting agency, Sebelius said in her blog post, with CMS spending $5.3 billion on contracting in 2013 alone. “We must take steps to ensure that our contractors are well managed, and that they fulfill their commitments and provide good services and products for our tax dollars,” she said.