A top Obama administration official who helped oversee the botched rollout of HealthCare.gov will retire on Tuesday, according to an announcement from the Centers for Medicare and Medicaid Services (CMS).

The departure of Michelle Snyder, chief operating officer of the CMS, is the second instance of an administration official leaving the agency since the Web site launched with a multitude of glitches in October, preventing many users from enrolling in health plans through the government’s online insurance exchange.

Tony Trenkle, who was CMS’s chief information officer prior to the rollout, left the agency in November.

CMS Administrator Marilyn Tavenner announced Snyder’s retirement in an e-mail to agency employees. “Michelle’s intelligence, experience and formidable work ethic have been indispensable to me and to many of you during her tenure,” she said.

Snyder, the highest-ranking official with responsibility over HealthCare.gov to leave the administration since site’s roll-out, has worked in public service for 41 years, including a stint as deputy chief operating officer for CMS. She helped the agency expand its community-based health-center programs, establish an employee-mentorship program and achieve its first clean financial audit, according to the announcement.

Despite early problems with HealthCare.gov, the site is functioning better after a series of fixes. The Obama administration said this week that more than 1.1 million Americans have signed up for insurance plans through the online portal.

The Department of Health and Human Services had projected a much higher 3.3 million people would enroll through the exchange by now, according to a September memo from the agency.

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