Prince George's County school board members and budget planners, faced with a voter-imposed ceiling on county property tax revenues, are already bracing themselves for what they feel may be major budgetary crunch next year.

Although some county officials have estimated that the entire county budget of $443 million may grow by only $6 million next year because of the TRIM charter amendment, school budget planners say they will need at least a $17 million increase, the same amount of increase the schools received in this year's budget, to maintain present services.

"It's going to be very tough this year," said Frank Platt, the school system budget director. "We are going to have real problems."

School officials are preparing an estimate for Superintendent Edward J. Feeney of the costs anticipated next year.

Although the study will not be completed until next week, Platt can already tick off more than $8 million in increases the schools will need: $2 million for cost-of-living salary raises, $4.5 million for incremental salary increases, $1 million for Social Security and health plan premium charges, $500,000 in increased utility rates and hundreds of thousands of dollars more to comply with new federal regulations for facilities for the handicapped.

The salary, premium and cost-of-living increases also may rise dramatically, Platt said, depending on the results of the schools' labor negotiations with its three unions, whose contracts expire next June 30.

School board members are clearly preparing for the crisis they expect to descend on them next month when Fenney submits his proposed budget to the board. At last week's meeting, members adopted a new meetings policy, inspired by the anticipated impact of TRIM, that will commit the board to spend half of its meetings evaluating present school programs, rather than considering new ones.

The new meetings policy, proposed by board member A. James Golato, has been adopted on a trial basis for January and February. If the board is able to keep up with its ongoing work in only one meeting a month, the new format will be adopted permanently.

"I think it's going to work well," said Golato. "We spend too much time on policy now, and we hardly ever evaluate anything. And when we don't evaluate our existing programs, there's a tendency to set one program on top of something that already exists.

"If we have less time to work on policy, I think we would be more discriminating about what we consider and what we spend."

The new meetings format was opposed only by board Chairman Norman Saunders, who later changed his vote to make the approval unanimous. Saunders said he was worried that pressing business would be neglected by the board because it could not be considered at half of the meetings.

However, Golato's proposal was amended so that new business may be taken up by the board at its oversight meetings upon the recommendation of the superintendent and approval by six of the nine board members.

Golato's resolution states that the oversight meetings should be devoted to items such as "efforts to expand and improve programs for the gifted and talented; effectiveness and reliability of existing testing methods; educational priorities to emphasize in the budget; reduction in numbers of English electives and textbooks in other subjects, (and the) existing busing program."

After adopting the oversight meeting plan, the board considered a proposal by Saunders that the board policy of meeting three times a year at a district high school be dropped.

Only one more meeting is scheduled for a high school this year, but Saunders said the move was necessary "because of what the voters showed they wanted by passing TRIM."

After some discussion, Saunders' proposal was tabled until this week's meeting and the school staff was asked to prepare an estimate of the cost of moving board meetings from Upper Marlboro to one of the high schools.

If the apparent anxiety of board members over the effects of TRIM on next year's budget is an indication, the resolution may pass, even if it saves the schools only a marginal amount.

"We are going to need a lot of dollars to stay where we are, and we a* re being put in a real crunch," said Golato. "Maybe we can tolerate what's been thrust on us this year. We might be able to scrape through only cutting muscle, but not bones. But then there's next year - and that's when we are really going to get hurt."