By Sarah Ferris - 01/16/15 10:19 AM EST
The leader of the agency charged with the ObamaCare rollout is stepping down after five years on the job.
Marilyn Tavenner, administrator of the Center for Medicaid and Medicare Services (CMS), announced her departure Friday, which will take effect next month.
"It is with sadness and mixed emotions that I write to tell you that February will be my last month serving as the administrator for CMS," Tavenner wrote in an email to staff.
Republicans on the House Oversight Committee last month grilled Tavenner about the miscount, which had helped push the first-year enrollment total for ObamaCare past 7 million — a milestone that was celebrated by the administration at the time.
Tavenner said some figures were “inadvertently” double-counted, an explanation that was greeted with deep skepticism from Rep. Darrell Issa (R-Calif.), whose staff identified the error.
“Tavenner had to go,” Issa wrote Friday in a statement provided first to The Hill.
“She presided over HHS as it deceptively padded the Obamacare enrollment numbers. It was a deplorable example of an agency trying to scam the American people. They weren’t successful this time because of Congressional oversight. We deserve better.”
In her letter to CMS staff, Tavenner cited the passage of the healthcare law in 2010 as the source of "many additional challenges," for the agency, while praising her staff for rising to the occasion.
"With those changes came a whole new set of responsibilities and a spotlight that brightly shown on all of us," she wrote.
"But with your hard work, dedication, commitment and resolve, you cleared the path and laid out a plan for all that we needed to accomplish. As a result, you are truly transforming healthcare in this country," she added.
With the rollout of ObamaCare, Tavenner also oversaw the country's largest expansion of Medicaid since its formation.
She touted what he portrayed as a series of other successes, such as a record of "clean financial audits," major steps to improve the healthcare delivery system and stronger efforts to combat fraud.
Tavenner has been one of the best-known faces of ObamaCare on the Hill as well as a close ally to Heath and Human Services Secretary Sylvia Mathews Burwell.
“Marilyn first joined the Department during 'snowmageddon' in February 2010. For the last half decade, she has insisted on pushing forward, no matter how severe the storms we faced,” Burwell wrote in an email to staff.
She described Tavener as “a big part of the reason” why 10 million people have signed up for healthcare under the law.
The CMS chief was tested during numerous hearings on ObamaCare, including a rough appearance alongside the administration’s embattled former adviser, Jonathan Gruber, before the House Oversight Committee in December.
Still, she maintained backing from many of the GOP's top leaders.
Sen. Orrin HatchOrrin HatchA bipartisan bright spot we can’t afford to pass up: child welfare reform Medicare trust fund running out of money fast Long past time to fix evidence-sharing across borders MORE (R-Utah) praised the departing official in a statement released just minutes after her announcement.
“Marilyn has done a great job in a very difficult position under near impossible circumstances,” Hatch, the chairman of the Senate Finance Committee, wrote in a statement.
“She has proven herself to be a strong leader and a straight-shooter who brought in much needed private sector sensibility into the agency,” he wrote.
Tavenner’s chief of staff, Aryana Khalid, also announced Friday that she would be leaving the agency.
The pair of departures come about a month after that of CMS’s deputy administrator, Cindy Mann. The agency’s No. 2 official left her post in January.
This story was updated at 1:37 p.m.