Barack Obama's health secretary, Kathleen Sebelius, is set to resign, six months after a disastrous rollout of the president's signature health law.
On Friday, Obama will nominate Sylvia Mathews Burwell, the director of the Office of Management and Budget, to replace Sebelius.
According to Politico, Sebelius, 65, gave no hint of her imminent resignation, as she testified before a Senate panel.
She announced that enrollment in Obamacare exchanges had surpassed 7.5 million - a figure that easily beat White House expectations.
A White House official said Sebelius told Obama in March that she planned to resign.
Sebelius earlier worked as a state insurance commissioner and Kansas governor, who was also the daughter of a former Ohio governor. She became one of Obama's longest-serving Cabinet members.
She was sworn in April 2009 and was the top federal health official through the tumultuous negotiation of the Affordable Care Act, the report added.
