More than 230,000 civil servants in six agencies will get retroactive pay of up to $90 because their agencies failed to keep pace with on-again, off-again congressional rules on how federal salaries are to be computed.

The General Accounting Office has informed the agencies -- which had asked if they could be excused from making the back payments -- that they should have kept abreast of bookkeeping changes made between October and March.

Back pay will go to employes in the State Department, the Department of Health and Human Services, the Federal Communications Commission, the Defense Logistics Agency, the General Services Administration and the Defense Contract Audit Agency.

As a temporary money-saver two years ago, Congress ordered agencies to stop computing pay on the basis of a 2,087-hour year and switch to a divisor of 2,080 hours.

The changeover saved the government millions of dollars and cost the average employe about $1.60 per week. Because workers got a raise just as the changeover went in effect, many didn't notice it until they read it in the newspaper.

The temporary system expired in September, but Congress made clear that it planned to make the 2,087-hour system permanent. As a result, some agencies didn't revert to the old 2,080-hour system. It took until March for Congress to make the changover official.

Media Corner

The Postal Employees Newsletter, which will cover news of interest to the country's 700,000 postal workers, makes its debut next week. It is published by the long-running Federal Employees News Digest, which is published by Joseph Young, former Washington Star columnist. Bob Williams, formerly with The Federal Times, will edit the new postal newsletter. Subscriptions are $29 a year. For information or a sample copy write to PEN, P.O. Box 7528, Falls Church 22046.

Bun Bray, retired director of the Federal Managers Association, has published "Braying About Washington," his insider's view of three decades of federal personnel changes.

During the years that he was staff director of the House Manpower Subcommittee, Bray was present at the creation of virtually every important piece of civil service legislation. Copies of his book can be had for $3.25 from Cardinal Press, 6628 Van Winkle Dr., Falls Church 22044.

Federal Times columnist Randall Shoemaker issued a nothing-is-forever warning in this week's issue about "guaranteed" benefits in a new federal pension plan.

Those benefits are based on Social Security, a modified civil service pension and a tax-deferred investment option. But Shoemaker points out that Congress can, and frequently does, take back what it gives.

"The government keeps changing retirement programs -- Social Security, civil service, military, private employer sponsored plans, IRAs," he wrote. "It changes vesting, tax breaks, cost-of-living adjustments, offset or age and service requirements and annuity formulas," and this "lack of commitment . . . has become a major worry for retirees" and should concern workers, too.

Federal Personnel Publications has just published its first Retired Military Almanac, which is directed at former service people. The $4.25, 204-page handbook has the latest in laws, rules and benefits concerning retirees. It also has a who-to-contact guide for information on VA benefits, combined civil service/military benefits and the like. For information call (703) 532-1631.