Marilyn Tavenner, the administrator of the federal Centers for Medicare and Medicaid Services, who oversaw the implementation of the Affordable Care Act, will step down.
Tavenner announced her departure on Friday in a message to staff.
"I have great pride and joy knowing all that we have accomplished together since I came on board five years ago in February of 2010," Tavenner said.
Tavenner was at the center of the problematic rollout of Obamacare, the president's signature domestic program. When the marketplaces were first introduced in October of 2010, the website was essentially useless.
After the mess, Obama shook up the staff, but Tavenner remained. After much controversy and congressional hearings, the problems were eventually solved.
In a message to staff, Secretary of Health and Human Services Sylvia Burwell called Tavenner "one of our most esteemed and accomplished colleagues."
On Obamacare specifically, Burwell said:
"It goes without saying that Marilyn will be remembered for her leadership in opening the Health Insurance Marketplace. In so doing, she worked day and night so that millions of Americans could finally obtain the security and peace of mind of quality health insurance at a price they could afford. It's a measure of her tenacity and dedication that after the tough initial rollout of HealthCare.gov, she helped right the ship, bringing aboard a systems integrator and overseeing an overhaul of the website.
"She is a big part of the reason why, as of this past spring, roughly 10 million Americans had gained health coverage since last year – the largest increase in four decades."