Many of the 175,000 retirement-age federal workers (including 27,000 here) are poised to leave this week based on nothing more than a gut feeling that it is now or never for the popular lump-sum pension option.

That benefit allows retirees to take a reduced lifetime annuity in exchange for a two-stage lump-sum payment that represents the amount of money they paid into the federal pension program.

About 70 percent of retirees take lump-sum payments. Such payments can be worth as much as $95,000 for high-paid, longtime employees. For the typical Washington area retiree, the benefit is about $30,000 before taxes.

A White House-congressional budget summit committee is studying the possibility of altering or eliminating the lump-sum benefit to save an estimated $1 billion a year. But the committee, which last met Aug. 3, won't meet again until next week. And any decision it makes on the lump-sum payment, which is only a minor item in the budget process, is unlikely to come before the end of September.

If the two-stage payout is changed or eliminated, only workers who retire in the next few days would be unaffected. The magic retirement date is Friday for people under the Federal Employees Retirement System and Monday for those under the old Civil Service Retirement System.

Anyone who retires now solely to cash in on the lump-sum pay will be acting almost entirely on speculation. Financial experts say that in most cases people should not let the lump-sum payment drive their retirement decision.

The bad news is that there is no news on the lump-sum situation. There won't be for a few weeks, if then.

If the benefit is eliminated or changed (please note the number of "ifs" in this column), people retiring this week will be the last to get it. In that case, they will have done the right thing.

But if the benefit isn't eliminated, it means people who suddenly end long careers this week will have guessed wrong. Many workers would like to stay on into 1991, when they are slated to get a 3.5 percent raise. Such an increase would raise retirement benefits for workers (because pensions are based on the highest three-year average salary) and also jack up the value of unused annual leave that workers are able to cash in when they retire. For some members of the Senior Executive Service, who are looking at much bigger percentage increases, annual leave balances could go up $10,000 or more with the advent of the pay raise. But if they stay for the raise, they run the risk of losing the lump-sum benefit.

The bottom line is that nobody knows anything about the lump-sum payment and nobody will know in time to help you make a retirement decision.

So, this is a decision, perhaps one of the most important you've faced in a long career, that you must make without all the facts. And make it alone! The cavalry -- in the form of a decision from the budget summit group -- is coming. But it won't arrive in time to do you any good.