The D.C. Department of Human Services, the city's largest and most troubled agency, is feeling the first tremors of the management shakeup promised by Mayor Sharon Pratt Dixon.

Five of the 34 District managers who have been asked to resign in the first wave of pink slips are high-ranking Human Services officials, including Social Services Commissioner Barbara Burke-Tatum and Vernon Hawkins, deputy director for program operations and analysis.

Dixon also is forcing out John Jackson, the agency's alcohol and drug abuse administrator, and Virginia Fleming, the deputy director of administration who has overseen contracting for the agency for three years.

Although some have praised Fleming for making the best of a chaotic situation she inherited, others hold her responsible for a contracting mess that looms as one of the department's more serious problems. The city currently is paying local groups to provide services in 260 cases without formal contracts. Other groups have contracts, but haven't been paid.

The Whitman-Walker Clinic, for example, has received no payment in a year from the District government on its $86,000 contract to operate a community alcoholism program that treats about 150 clients a year. The private, nonprofit organization also lacks formal contracts for $709,000 in health and social services that it provides for the city.

Vincent C. Gray, the mayor's appointee to head the $1 billion-a-year agency, takes over next Tuesday.

Gray will be the department's ninth director or acting director since 1980. The frequent management turnover has added to the problems of an agency that has been racked for years by contracting scandals, budget problems, court orders, cronyism and chronic mismanagement.

The department oversees programs such as Medicaid, Aid to Families with Dependent Children, St. Elizabeths Hospital and public health and drug treatment clinics, as well as services for people who are disabled, homeless, mentally retarded or abused.

Among the problems and policy decisions facing the new administration: How to comply with a court order to deinstitutionalize hundreds of St. Elizabeths patients who no longer need hospitalization when the District has not yet created community-based housing and programs for them.

How to provide health care for the more than 100,000 D.C. residents who do not have health insurance at a time when indigent care is draining the city's finances.

How to limit eligibility for Medicaid and Aid to Families with Dependent Children to save money.

How to provide better care for the 2,200 abused children in the District's child welfare system. According to a class-action lawsuit filed by a children's advocacy group, the system is overwhelmed and underfunded and warehouses children for years in foster care instead of finding adoptive parents.

How to restructure the agency to provide services more efficiently. The Rivlin Commission study of city operations and expenses recommended dividing it into two parts, consolidating some offices and eliminating others.

Gray "is well aware of the difficulties that lie ahead at DHS" and "does have a management team in the wings," agency spokesman Larry Brown said last week. "He'll be ready to start doing business Feb. 19."

Some officials say the agency has been rudderless and adrift for four years, while Mayor Marion Barry was embroiled in controversy and faced drug charges.

"A lot of things are on hold because nobody knows who's going to stay and who's going to go," said Claudia Schlosberg, coordinator of a watchdog group that monitors the city's compliance with a court order to improve treatment of the mentally ill. "And the system is in crisis."

The five managers asked to resign Feb. 1 are among 177 political appointees whom the mayor can replace. Some already have left on their own. Some have the right to remain in the government in some lower job. The decision of whom to let go is being made by the mayor's staff, usually in consultation with the new agency head, on a case-by-case basis, said Acting D.C. Personnel Director Lorraine Green.

"It's her prerogative to keep or dismiss whom she wants," said D.C. Council member H.R. Crawford (D-Ward 7), chairman of the commitee with oversight of the Department of Human Services. "I agree with the mayor that there needs to be change at the top."