The Maryland agency that regulates hospital costs alleged today that Doctors' Hospital of Prince George's County has overcharged patients by nearly $800,000 since its opening in 1975.

A Maryland Health Services Cost Review Commission analyst said the 230-bed private hospital in Lanham apparently had exceeded the commission's approved rate schedules by $400,700 for use of its emergency room, $170,000 for its operating room, $175,100 for electrocardiogram tests and $23,000 for its intensive care unit.

Officials of the hospital were summoned by the commission to explain the alleged overcharging at a public hearing. The hospital could be asked to refund the money to patients if the commission supports the charges.

Harold A. Cohen, executive director of the regulatory commission, said today's action was the first time that the 5-year-old state agency had called for a hearing to see if its orders had been followed.

The analyst's report found the alleged overcharging from June 26, 1975, when the hospital opened, through last Sept. 30. It said a similar pattern of overcharges existed in the last quarter of 1976 "but to a lesser extent."

State analysts also found that "total revenue for inhalation therapy, pharmacy and medical supplies is extremely high compared to other Maryland hospitals in the Washington area." They noted, for example, that revenue in those departments at Doctors' was greater than at the much larger, 635-bed Prince George's General Hospital during the same period.

Dr. Leon R. Levitsky, the president and prinicipal owner of the hospital on Good Luck Road, could not be reached for comment tonight.

No date was set for the hearing on the compliance order or for a second one called to determine why the hospital allegedly has failed to file quarterly reports containing information about charges for various other medical services being performed by outside groups.

Rate analysts said they were unable to determine the charges being made by the hospital in seven areas - radiology, nuclear medicine, laboratory, blood bank, respiratory therapy, pharmacy and CAT scanner. The auditors said Dr. Levitsky and Robert Goner, vice president for finance, contend that because those services are contracted out, they are not within the commission's jurisdiction.

Gonder attended today's commission meeting but made no comment.

Staff members of the Cost Review Commission visited the hospital on April 25, 26 and 27 as part of the agency's regular rate review process,' to see if the hospital was complying with approved rate schedules. The hospital has no connection to Doctors Hospital in the District or to Northern Virginia Doctors Hospital.

Overall costs at the new Prince George's hospital also are extremely high when compared to other hospitals in Maryland, according to audited reports on file at the commission. The cost of care per patient day at Doctors' for the year ending March 30, 1976 (latest figures available) was $221, much higher than other hospitals in suburban Maryland and third highest among the 59 hospitals in the state. Only Johns Hopkins and University, the state's two major teaching hospitals, had higher daily cost, at $237 and $255 respectively.

By comparison, the comparable fig-Holy Cross, $165; Leland Memorial, $164; Montgomery General, $180; Prince George's General, $184; Suburban, $139, and Washington Adventist, $166.

Another privately operated hospital that opened about the same time as Prince George's Doctors," Fallston in Harford County, reported a daily per patient cost of $131.

One person familiar with hospital rates said that proprietary hospitals "often brag that they are cheaper bcause the profit motive gives them an incentive to keep costs down, but that hasn't happened at Doctors'."

The commission's study found that pharmacy costs per patient day at Doctors' averaged $11.07, while the other six area hospitals averaged about $8 for daily drug charges.

Cost of inhalation therapy (oxygon) at Doctors' averaged $15 a day, compared to a low of $2.51 and a high of $6.17 at the other six, the study found.

Central supply cost at Doctors' was $25 a day, compared to a low of $2.85 and a high of $6.62 at the other six, according to the study.