D.C. Deputy Mayor for Health and Human Services HyeSook Chung, right, with Mayor Muriel E. Bowser (D) during the city’s 2017 homeless count. The mayor’s office said Chung is leaving the administration. (Amanda Voisard/For the Washington Post)

For the second time in less than a week, D.C. Mayor Muriel E. Bowser (D) has announced that one of her top aides is departing.

Deputy Mayor for Health and Human Services HyeSook Chung, who oversaw the District’s sprawling and high-budget array of social service agencies, was placed on administrative leave on Wednesday and will not return to work, the mayor’s spokeswoman said. She declined to say why. Chung’s last day will be Oct. 10, the spokeswoman said.

D.C. Department of Health Care Finance Director Wayne Turnage will replace her on a temporary basis while continuing to do his current job, according to an email City Administrator Rashad M. Young sent to other cabinet officials Wednesday night.

Chung was appointed less than two years ago. It was not clear what prompted her exit, which comes after Deputy Mayor for Greater Economic Opportunity Courtney Snowden announced she was leaving last week.

Chung’s departure was first reported by WAMU-88.5.

Coming at the end of Bowser’s first term — the mayor is running for reelection this fall without serious opposition — some amount of turnover is to be expected. John Falcicchio, Bowser’s chief of staff, released a statement batting away the notion that the sudden turnover in the top ranks of the Bowser administration was unusual.

“We have a great team — many of whom have served our residents since the first days of the Bowser Administration,” Falcicchio said. “After more than three and a half years, it is ordinary that some will take on new roles and others will seek opportunities outside of government. We are thankful to all who serve.”

Chung could not be reached for comment.

D.C. directly manages a large portfolio of social and health services — unlike other cities, where those functions are typically performed by counties and states. Chung, who was named to her position in December 2016, was nominally in charge of agencies including the Department of Human Services — tasked with reducing the District’s high rate of homelessness — and the health care finance department, which runs D.C.’s Medicaid program.

The Bowser administration has repeatedly been embarrassed by developments in Chung’s policy area, including scandals at the District’s public hospital, United Medical Center, and delays in the mayor’s landmark plan to rebuild the shelter system for homeless families. Those delays helped prompt an audit of the city’s homelessness programs that the D.C. inspector general is now conducting.

D.C. Council member and health committee chairman Vincent C. Gray (D-Ward 7) said he did not believe Chung did enough to address racial and class disparities in the quality of health care across the District. He said she wasn’t sufficiently hands-on when it came to planning a new hospital and expanding medical care east of the Anacostia River.

“I never saw her get into the nuts and bolts of why it was important to have a real health-care system on the east end of the city,” said Gray, a former mayor whom Bowser unseated in 2014. “I never saw any demonstration of the leadership that I know is necessary from the deputy mayor’s office.”

A Bowser spokeswoman declined to comment on Gray’s criticism or say whether there was a specific reason for Chung’s departure.

Last month Bowser announced a tentative agreement between the District and George Washington University Hospital to partner on opening a new hospital in Southeast Washington in 2023.