D.C. school offficials said yesterday they will need $27 million more than Mayor Marion Barry wants to give them next year in order to avoid laying off more than 200 employees -- most of them teachers.

The additional layoffs would bring to nearly 900 the number of job reductions over the last year in the city's troubled school system. Yesterday school officials charged that the school system has had to bear the brunt of Mayor Marion Barry's efforts to resolve the District government's worsening financial crisis.

School officials said their million request represents a "bare bones, standstill" budget, which will merely enable them to keep the same programs and at staff levels they had this year.

But Barry immediately labled the request "irresponsible" and "nothing short of capriciousness."

Barry accused the school board members of "lack of responsiveness and lack of seriousness" for forwarding him a budget that did not list by item how the money was to be spent.

He reiterated that he plans to send a request for a $238.2 million school budget to the City Council in October if he does not get the more detailed information from the school system.

At a press conference yesterday, John E. Warren, chairman of the board's budget would not allow the school system to start any major new programs or restore programs cut last year.

"I think we can get by on this budget. But with our new [high school] curriculum, and the increased required courses, particularly in the area of foreign languages, we're going to need some flexibility and we're not going to have it," Warren said.

Warren also announced a series of public hearings to be held later this month in which citizens will be able to "prioritize" for school officials what programs they want kept in the schools, and what programs they want restores.

He added, however, that none of the programs eliminated this year, including full-day prekindergarten and some adult education programs -- are currently in the 1982 budget. There is also no funding for driver education, which was restored this year after the Geico Corp. offered to give a one-time $600,000 donation to the school system to keep the program going.

Warren said that other current programs would have to be cut if any of the old programs are to be restored.

"There is no question," said board member Frank Smith (Ward 1), "that we will have to release several hundred more teachers or else shorten the school year" if the mayor's lower budget request is approved.

Hammering at a familiar complaint of school officials, Smith said, "No other city agency has fired anyone near the number of employes we have" to comply with the budget cuts Barry ordered for this fiscal year.

Barry said his budget allocation of $238 million is based on the assumption that the enrollment in the schools will decline by 6,600 students in 1981-1982 school year, to about 92,000 and that "a number" of school buildings will be closed and less staff needed.