The Office of Management and Budget, which often engages in sparring matches with agencies in the early days of the annual budget season, hasn't even shown up in the ring yet. Its low profile so far in this election year stands in marked contrast to last fall, when Director David A. Stockman, reinforced by President Reagan, was leaning hard on agencies to keep their budgets under rigorous levels and to hand over budget proposals promptly for OMB vetting.

This year, budget ceilings are higher. (OMB spokesman Edwin L. Dale Jr. says this decision was made long ago and is reflected in the long-term spending projections contained in the budget for fiscal 1985.) At least one major budget (for the Health and Human Services Department) is weeks late and may not reach OMB before the election, but not a word of protest has been heard. (Dale said it is routine for HHS to be late.)

According to several sources, agency budgeteers have been advised not to send proposals to OMB that could embarrass the Reagan administration if they managed to leak before the Nov. 6 election. Democratic observers say it is convenient that HHS has not been heard from, since the major items in its budget -- Social Security, Medicare and Medicaid -- are among the most sensitive political issues for the president.

Those items have been handled carefully for some time now -- at least since August, when OMB presented its mid-session budget review to Congress. As one old OMB hand put it, "Traditionally, OMB in its mid-session review is rather obstinate," sticking to the original budget proposals no matter how thoroughly Congress has rejected them.

This year, however, the agency's three-year projections for Medicaid and Medicare spending through fiscal 1987 were more than $6 billion higher in August than the administration originally projected in January. Instead of using the original estimates -- being "obstinate" -- OMB incorporated the policy changes passed by Congress in the Deficit Reduction Act and so projected higher spending levels in these politically popular programs. The same thing happened with the Agriculture Department's commodity price support program.

Dale, however, said that previous years' mid-session reviews similarly have reflected "enacted legislation." "In the case of Medicare, we made a judgment that policy decisions were finished for the year . . . . It is unusual for Congress to do such sweeping and substantive legislation this early."

Asked if the election had anything to do with it, Dale replied, "It just never came up in that context. The election had nothing whatever to do with the technical decision."

In some respects, he added, the administration is sticking to its guns: some of OMB's August figures reflected proposals that were clearly destined for defeat, including elimination of the Legal Services Corp. and a proposal to tax health insurance premiums paid by private employers if the premiums exceed a specified level. NEW FACE . . .

Over on the management side of the agency, some new faces have appeared in the division that deals with state and local governments. John W. Merck, who had headed the staff that reviews the Veterans Administration budget, is now deputy associate director for planning and community management, replacing James F. Kelly. Merck's place in the budget shop has been taken by Susan S. Jacobs.