A special state-commissioned study of Maryland's underused hospitals says up to 14 facilities -- including five in the Washington area -- may have to be closed or merged and thousands of surplus beds eliminated at others to cut spiraling costs, official sources said today.

According to the study, set for release Wednesday by the State Health Resources Planning Commission, more than 1,000 beds would have to be eliminated in Prince George's and Montgomery counties by 1988 and 2,585 in Baltimore to rid hospitals of their low occupancy rates.

Maryland hospitals on the average are 66 percent full, a rate that is about the same as the national average.

Public hearings on the study, which is expected to stir controversy among hospital professionals and local politicians seeking to protect facilities on their turf, are scheduled for later this summer.

After that, the planning commission will likely adopt some modified form of the study as the official state plan for future hospital development. The planning commission has the authority to revoke hospitals' licenses.

The study, conducted by the national management consulting firm Booz-Allen & Hamilton for the planning commission, covers the state's 54 general service hospitals where an estimated 5,126 of 15,600 beds are empty.

Under a series of suggested options, the sources said, the study names five hospitals among the 11 nonmilitary hospitals in Prince George's and Montgomery counties that could be closed or merged with other institutions: Washington Adventist Hospital in Takoma Park, Montgomery General Hospital in Olney, Doctors' Hospital of Prince George's County in Lanham, Leland Memorial Hospital in Riverdale and Clinton Community Hospital.

Three other hospitals could be closed or merged in Baltimore as well as a number of small institutions in rural areas of the Eastern Shore and western Maryland, the sources said.

The 210-page study was described by sources familiar with it as couched in neutral terms to avoid the appearance of being a "hit list" of hospitals.

It contains no recommendations for closings or bed reductions, sources said, but simply outlines a series of possible "options" for the planning commission to eliminate surplus beds.

Hospitals in each county and in Baltimore City are ranked in terms of their cost efficiency, geographical and economic accessibility and quality of service, according to the sources.

Lower ranking hospitals generally are assigned a greater number of bed reductions than higher ranking institutions, the sources said, with the lowest slated for closing or merger.

One hospital official criticized the study. "It comes as quite a surprise," said Reg Burgess, vice president for communications at the 320-bed, 1,300-employe Washington Adventist Hospital in Montgomery County. "There's very little logic in closing down the most cost-effective hospital in the county."

He said Washington Adventist boasts a successful open heart surgery program and is scheduled to open a $3 million cancer department in September.

Administrators at Montgomery General, Leland Memorial, Clinton Community and Doctors' Hospital of Prince George's County either declined to comment or were unavailable.

Hospital labor union leaders, many of whose members have suffered layoffs in recent months because of cutbacks, also took a wait-and-see attitude, mixed with skepticism.

Ron Hollie, local president of the National Union of Hospital and Health Care Employees, said he had not yet been fully briefed on the study.

But Hollie, who leads the union representing clerical and maintenance workers at six Baltimore hospitals, said, "I know I'm going to have problems with it . . . . I suspect some of their figures are antiquated."

State legislative members, many of whom helped write a package of hospital cost containment measures last winter that authorized the study of surplus beds, rose to the defense of hospitals in their districts.

Sen. Stewart Bainum (D-Montgomery) said he was "surprised and dismayed" at the idea of possibly closing Washington Adventist. "It seems quite unwarranted to me."

Sen. Thomas V. Mike Miller (D-Prince George's) said closing Doctors' Hospital in his county would be a "travesty . . . . It serves a very large community of people . . . and the quality of medical care there is absolutely excellent."

The study appears destined to provoke a public outcry. In Baltimore, for example, Mayor William Donald Schaefer fought to keep Maryland General Hospital, one of those listed in the study for possible closing, from being moved to Baltimore County.

Maryland General also is in the legislative district of Del. Larry Young, chairman of the House Environmental Matters Committee with oversight over health matters. "If this plan is adopted," Young said today, "it would be devastating."

Young and other officials stressed that publication of the study is only the first step in a public process of hearings and reviews before the health resources planning commission adopts a plan for hospital development.

Officials of the state Department of Health and Mental Hygiene have stressed in the past that, even without state intervention, hospitals are going to shrink because of declining admissions and shorter hospital stays.

Comprehensive planning at the state level thus is needed to assure an orderly process, they said. Recent legislation also is designed to provide incentives for mergers and closings, they said, such as higher hospital rate-setting allowances for transitions and employe job training.