District of Columbia mayor-elect Muriel Bowser participates in her final city council meeting on December 17, 2014 in Washington, DC. (Jonathan Newton/The Washington Post)

Mayor-elect Muriel E. Bowser on Monday appointed a trio of officials with ties to the administration of former mayor Adrian M. Fenty (D) to lead key D.C. social service agencies.

To direct the Department of Human Services, Bowser (D) is tapping Laura Green Zeilinger, who was deputy director of that agency during the Fenty administration and serves as executive director of the U.S. Interagency Council on Homelessness.

“Now is the right time to make meaningful change locally, and I really wanted to be part of that,” Zeilinger said after a news conference announcing her appointment. The announcement was made at Miriam’s Kitchen, a Foggy Bottom nonprofit that serves the homeless.

Zeilinger will oversee a diverse portfolio of social services, including the city’s welfare program, food benefits, child-care assistance and adult protective services. But no aspect of her duties will be more closely watched than the department’s efforts to aid the homeless.

Homelessness became a nettlesome realm of policy and politics for outgoing Mayor Vincent C. Gray (D) as families burdened by economic difficulty and escalating housing prices in recent years overwhelmed the city’s infrastructure — including the large, decaying family shelter in the former D.C. General Hospital.

Bowser, who will be sworn into office Friday, echoed previous mayors in saying that she was committed to ending chronic homelessness in the city. She reiterated plans to move toward closing the D.C. General shelter, though a timeline has been elusive.

“My focus is not on creating more shelter but on creating new housing opportunities,” she said.

Zeilinger said she would ensure her department was operating “efficiently and with urgency” to get families out of shelter beds and into more permanent housing to maintain emergency shelter capacity at D.C. General and motels.

During the Fenty administration, Zeilinger was tasked with developing “housing-first” services for the chronically homeless, who are placed in permanent housing and supported with other services — including treatment for mental illness and/or substance abuse.

Those programs were widely hailed, but their expansion was curtailed in recent years when federal funding waned. Zeilinger said she hoped to find new funding streams for the housing-first model.

“We were making a lot of headway in really helping people who were falling through the cracks,” she said. “That’s something that’s important to pick up. . . . We have to understand the strategies and the resources available and how to make those resources work in a different way.”

Zeilinger is taking over a massive city bureaucracy that has been under interim leadership since June, when human services director David A. Berns retired after three years in the job.

Bowser also named two other cabinet nominees Monday. Both are government officials in other cities and were not present at the news conference.

The incoming mayor’s choice to lead the Department of Health is LaQuandra Nesbitt, a board-certified family physician who is leaving a post directing the public health and wellness department in Louisville.

Before assuming the Louisville job in 2011, Nesbitt served as a senior deputy director of the D.C. Health Department, overseeing the agency’s community health efforts — including nutrition and physical fitness programs, cancer and diabetes prevention, and infant and child health improvement.

Nesbitt will replace Joxel Garcia, also a medical doctor, who has served as health director since August 2013.

“We’re sorry to see her go,” Louisville Mayor Greg Fischer said in a phone interview Monday. “D.C. has picked up a very qualified individual.”

Fischer said Nesbitt took a leading role in developing a long-term public health strategy for Louisville and participated in a cross-agency effort to reduce violent crime in the city.

To lead the District’s closely watched juvenile justice department, Bowser is turning to Clinton Lacey, who is deputy commissioner of the New York City Department of Probation.

Lacey has not previously worked in the District but served in New York under Vincent N. Schiraldi, a former director of the D.C. Department of Youth Rehabilitation Services under Fenty.

Lacey will take over leadership of the youth rehabilitation agency from Neil A. Stanley, a lawyer and veteran city official who has led the department since 2011.

His appointment could mean a recommitment to the reform efforts championed by Schiraldi, who won kudos from youth advocates for moving away from a juvenile justice system focused on incarceration — notably overseeing the closing of the troubled Oak Hill Youth Center — but encountered fierce criticism after missteps that included a series of escapes from the facility that replaced Oak Hill.

Lacey has served in various juvenile justice posts over the past two decades, though his job in New York concerns adult probation. From 1992 to 2004, he was associate executive director of Friends of Island Academy, developing and managing services for 16-to-24-year-olds involved in New York’s juvenile and criminal justice systems.

All three nominations are subject to D.C. Council approval. The Bowser transition team did not immediately make available salary information for the appointees.