WASHINGTON — A former executive at software giant Microsoft is assuming oversight of the Obama administration’s efforts to repair the troubled HealthCare.gov website, the Department of Health and Human Services announced Tuesday.

Kurt DelBene, who most recently served as president of the Microsoft Office Division, will take over from Jeffrey Zeints, a management expert whom the president asked to rescue the site after its disastrous rollout on Oct. 1.

Zeints is widely credited with helping to make the site functional, allowing tens of thousands of Americans to select a health insurance plan on marketplaces created by the president’s 2010 health law.

Over the last 2-1/2 months, federal officials and private contractors have dramatically cut errors and improved performance on the site, but insurance companies and others say there are lingering problems with the enrollment system.

Health and Human Services Secretary Kathleen Sebelius said in a blog post Tuesday that DelBene will begin work Wednesday and has agreed to serve at least through the first half of next year.

“First, Kurt will provide management expertise, operations oversight, and critical advice on additional enrollment channels, field operations, marketing and communications,” Sebelius wrote.

“Second, Kurt will execute the plan in place, so that we can ensure the site’s performance is strong through the close of open enrollment on March 31, 2014. This will include a focus on increasing system stability, redundancy and capacity, and building on improvements to the user interface, while continuing to prioritize security and privacy issues in line with industry best practices.”

The Department of Health and Human Services would not say how much DelBene will be paid. But an administration official said he would effectively do the work pro-bono as he intends to return his salary to the government.

DelBene is married to Rep. Suzan DelBene, a first-term Democrat from Washington state.