(www.cms.gov)

A top Obama administration official directly overseeing the rollout of HealthCare.gov and other aspects of the Affordable Care Act will abruptly retire at the end of the year.

Michelle Snyder, the chief operating officer at the Centers for Medicare and Medicaid Services, will leave her post this week, the agency confirmed to ABC News.

Snyder is the second high-level departure from CMS since the troubled launch of the federal online insurance portal in October. In early November, CMS chief information officer Tony Trenkle, who reported to Snyder, quietly announced his retirement.

In an email to staff today, CMS administrator Marilyn Tavenner hailed Snyder's 41 years of public service as a "distinguished career," but made no explicit mention of her role in the health law implementation.

Snyder, who is second in command at CMS, has had "overall responsibility for facilitating the coordination, integration and execution of CMS policies and activities," according to her official job description on the agency website. Her role was also to "promote accountability, communication, coordination and facilitation" of decision-making on key projects, including HealthCare.gov.

"Michelle's intelligence, experience and formidable work ethic have been indispensable to me and to many of you during her tenure," Tavenner wrote. "While the agency is losing a key member of its leadership team, we should celebrate Michelle's dedication to a mission that provides vital health care services to tens of millions of our fellow Americans through the Medicare and Medicaid programs."

Tavenner suggested that Snyder had put off retirement at the end of 2012 to assist "with the challenges facing CMS in 2013." An administration official said the decision to retire before 2014 was her own.

A report released by the Department of Health and Human Services in early December cited "inadequate management oversight and coordination among technical teams" as primary factors in the problems that plagued the website's rollout.

"The conclusion was that HealthCare.gov was fixable if we made significant changes to the management approach," said Jeff Zients, the administration official brought in to lead the repair effort, during an after-action briefing with reporters.

"We needed to get the team working with the speed and urgency of a high-performing private sector tech company," he said. The implication is that the team had not been sufficiently motivated or directed ahead of the Oct. 1 launch.

No other Obama administration officials directly responsible for the project have been fired or disciplined.