Federal workers who want to retire before Congress changes their pension tax status have weeks, maybe months, before they must make a decision.

It is possible that the proposal, which has many of the government's 200,000 retirement-age employes on edge, won't happen. At a time when everybody wants answers, there simply aren't any.

The change in federal pension tax rules is linked to the much bigger issue of tax reform. There won't be any change in the system that allows federal retirees to draw tax-free pensions for up to three years unless it is made part of tax reform, and unless Congress approves the politically explosive reform package.

The tax reform plan already approved by the House would wipe out by July 1 the ability of retirees to draw tax-free pensions until their previously taxed contributions are recovered. But the Senate has yet to be heard from.

The Senate's tentative tax reform plan is very different.

Among other things, it would phase out the tax-free period over two years, beginning in January 1988. That plan, from the Finance Committee, could be killed or changed by the full Senate before it approves any reform bill.

Next the bill must go to a House-Senate conference to iron out major differences. Then it goes to the president. Long-suffering readers know that tax reform is a drawn-out process, because so many special interests are involved.

If pension tax rules are changed, that law could make the change prospective or immediate. It could even be backdated.

Federal and postal unions and professional groups have been working on the Hill to protect pension benefits, and thus far have helped prevent the tough House plan from being incorporated into the Senate package. But things are moving so fast now even the best lobbyists can't keep up with changes and backtracking in Congress.

The point is that nobody knows what Congress will do eventually on tax reform or what effective date (or dates) various provisions may carry if tax reform becomes law. But given the hurdles the bill must still clear, it is unlikely that U.S. workers will have to make an overnight decision whether to retire. Breakfast of Champions

Office of Personnel Management Director Constance Horner will lead a national tribute to federal, state and local government workers at a breakfast meeting tomorrow at the Rayburn House Office Building. It is sponsored by the Public Employees Roundtable.

PER is made up of 24 organizations dedicated to improving the image of government workers. Agencies to be honored tomorrow are Army's Community and Family Support Center, the Minnesota Department of Agriculture and the Anne Arundel County Department of Utilities. For details of the session call PER, 535-4324. Aetna Refunds

Feds and retirees who had Aetna health insurance last year should get premium refunds soon.

Aetna says the first of more than 200,000 refunds were mailed last week, and that all the checks should be delivered by mid-month.

Refunds for nonpostal workers are: $33.50 for standard self-only coverage and $71.65 for family coverage; $157.34 for high-option self-only and $202.04 for family coverage. For postal workers the refunds are $2.10 for standard self-only coverage and $4.47 for family coverage; $96.74 for high-option self-only coverage and $95.82 for family coverage.

Postal workers get smaller refunds because the Postal Service pays a larger share of their premium.