More than 28,000 federal workers who needed cash to buy houses, for tuition, medical bills or other major financial hardships have borrowed $66 million from their tax-deferred thrift savings plan accounts since the option was made available 2 1/2 years ago.

The borrow-from-yourself option is one of the key features of the savings plan, which is now growing by about $10 million each workday. More than half of the nearly 3 million federal workers have savings plan accounts, which are part of their overall retirement program.

The thrift savings plan is the federal government's version of the 401(k) plan available to private sector workers.

In the federal plan, workers in the new Federal Employees Retirement System can put up to 10 percent of their salary into the tax-deferred investment accounts and get a matching 5 percent payment from the government.

Workers under the old Civil Service Retirement System can invest up to 5 percent of their pay.

Starting next year workers will be able to make unrestricted investments into the Treasury, stock market or bond market options of their plans.

Many similar private sector plans allow workers to make emergency withdrawals, but not as loans.

The federal savings plan requires that workers borrow (and repay with interest). That way their accounts don't shrink and they don't lose their tax-free benefits.

Minimum loans in the federal savings plan are for $1,000. And the money borrowed must come from the employee contributions, not from any government contribution to the savings plan account.Other Financial Help

Federal workers also can apply for loans, grants and tuition help from the privately run Federal Employee Education and Assistance Fund. It has provided $225,000 in hardship assistance and another $190,000 in scholarships.

The fund is part of the Combined Federal Campaign. It has been endorsed by major federal employee unions.

Its address is P.O. Box 2811, Washington, D.C. 20013-2811.Lump-Sum Update

Lots of people want to know what Congress will do with the popular lump-sum pension option. Welcome to the club!

Nobody knows what, if anything, will happen, or when Congress will decide.

Retirees now get lump-sum benefits in two equal payments. The 50-50 split ends Oct. 1 (and reverts to a single payment) unless Congress extends the current payout, decides on another split arrangment or abolishes it. The congressional-White House budget summit is considering whether to keep, change or eliminate the lump-sum benefit option.

On Aug. 11 WNTR radio (1050 AM) will have a one-hour special starting at noon on the lump-sum situation. Terry E. Zerwick, an Alexandria certified public accountant, will talk about the computer model he's designed to help people decide whether to take the lump-sum payments.