Health and Human Services Secretary Kathleen Sebelius will resign from her position on Friday, an administration official confirmed Thursday.
President Obama will nominate Sylvia Mathews Burwell, current director of the Office of Management and Budget, to take her place.
Sebelius, who has run HHS since the start of the Obama administration, oversaw the botched rollout of Healthcare.gov. She faced multiple calls for resignation in the fall, after the website meant to get millions of Americans' into new health insurance plans barely functioned for its first two months.
The health law's rollout did improve in early 2014, with a surge in private insurance enrollment in late March just before the end of open enrollment. Sebelius testified before Congress earlier on Thursday that private insurance sign-ups so far total at least 7.5 million, slightly higher than initial projections.
Sebelius notified the president of her decision to resign in early March, the same official said. At that time, she told the President she felt confident in the health law's increasing enrollment numbers and that it was an appropriate time for her to transition out of her leadership position.
Bloomberg broke the news of Sebelius' resignation late Thursday.