WASHINGTON - Kathleen Sebelius, the health and human services secretary, ended a stormy, five-year tenure marred by the disastrous rollout of President Barack Obama's signature legislative achievement, the Affordable Care Act.
Obama accepted her resignation this week, and he will put Sylvia Mathews Burwell, the director of the Office of Management and Budget, in play to replace her, officials said.
The departure comes as the Obama administration tries to move beyond its early stumbles in carrying out the law, convince a still-skeptical public of its lasting benefits and help Democratic incumbents who face blistering attack ads after supporting the legislation survive the midterm elections this fall.
Officials said Sebelius, 65, made the decision to resign and was not forced out. But the frustration at the White House over her performance had become increasingly clear, as administration aides worried that the crippling problems at HealthCare.gov, the website set up to enroll Americans in insurance exchanges, would result in lasting damage to the president's legacy.
Last week, as Obama announced that enrollments in the exchanges had exceeded 7 million, she did not appear next to him for the news conference in the Rose Garden. Enrollment has since risen to 7.5 million.
Sen. Pat Roberts, R-Kansas, a longtime family friend of Sebelius, was among the first to call for her resignation back in October. Roberts, who questioned Sebelius on Thursday during a Senate Finance Committee hearing, said her resignation "was a prudent decision that was overdue, given the failures of Obamacare."
The president is hoping that Burwell, 48, a Harvard- and Oxford-educated West Virginia native with a background in economic policy, will bring an intense focus and management acumen to the department. The budget office, which she has overseen since April of last year, is deeply involved in developing and carrying out health care policy.
Last month, Sebelius approached Obama and began a series of conversations about her future, said Denis McDonough, the White House chief of staff.
The secretary told the president that the March 31 deadline for sign-ups under the health care law - and the rising enrollment numbers - provided an opportunity for change and that he would be best served by someone who was not the target of so much political ire, McDonough said.
The resignation is a low point in what has been a remarkable career for Sebelius, who as governor of Kansas was named by Time magazine as one of the five best governors in the country and was even mentioned as a possible Obama running mate in 2008.
The two had bonded when Sebelius endorsed his presidential bid early in 2008, becoming one of the highest-profile Democratic women to back him over Hillary Rodham Clinton and helping him deliver a big win in the Kansas caucus.
White House officials were quick to point out the many successes during Sebelius' tenure: the end to pre-existing conditions as a bar to insurance, the ability for young people to stay on their parents' insurance and the reduction in the growth of health care costs.
McDonough praised Sebelius as "a fierce advocate" and said she had been "tenacious in her belief" in the president's health care law.
"She's fearless in her defense of this idea at the heart of the Affordable Care Act," he said. "The president has commented to me countless times how much he admires that."
Statesman Washington Bureau contributed.