Among the most confused people in town are the 100,000 federal and military retirees who are trying to figure out what the Senate is doing to the cost-of-living raise due them next January.

The reason for their confusion: The Senate, under tremendous political pressure because of the Social Security issue, is having a hard time making up its mind about what kind of budget cuts to make, if any.

In the past few weeks the Senate has taken three different positions on what to do about cost-of-living raises for retirees.

Postion one, from the Senate Budget Committee, was to freeze all civil service, military and Social Security retirement benefits next year and to make no inflation adjustments during 1986.

That plan was replaced by a compromise, worked out by the White House and Senate GOP leaders, to give partial cost-of-living protection to all retirees during the next three years.

The third and most recent (but not yet final) position is to give all retirees a full cost-of-living raise next year. That pleases the retirees, but doesn't do much about reducing the deficit. Here's the Senate score card to date:

Early last week the Senate okayed a White House-GOP leadership plan; it replaced the pension freeze budget recommended by the Senate's Budget Committee.

Under the complicated substitute, retirees would get minimum (2 percent) raises in each of the next three years. However, if inflation exceeded 4 percent a year, retirees would get raises that were 2 percent less than the actual total rise in living costs.

That proposal didn't sit well with either the Social Security or civil service pension lobbies. Those advocates argued, correctly, that any such "temporary" restructuring of the system would probably be made permanent by future budget-cutters in Congress. That in turn would mean retirees could fall 2 percent behind the rise in living costs each year, putting many of them at poverty level in a relatively short period of time.

Reacting to pressure two days later, the Senate reversed itself. It voted to restore full cost-of-living raises to the retirees. As of late yesterday that is where the Senate budget process stood.

It will probably change again, however. Ultimately, federal-military retirees will probably get the same deal as persons under Social Security.

What that will be is anybody's guess. More amendments will be voted on this week. Any one of the three benefit plans outlined above could be approved, or another compromise worked out.

It will be weeks, perhaps months, before Congress and the White House agree to a final spending plan for the fiscal year that begins in October. Until that plan is signed, sealed and delivered, U.S. workers and retirees won't know what is in store for them next year.