The Senate decision to deny full dependent social security benefits to anybody getting a public pension would hit an estimated 85,000 federal and public retirees in the first year, if it is enacted into law.

Under the controversial "offset" provision of the social security financing bill cleared by the Senate, no future federal, state or local government retiree could qualify for a full dependent social security benefit earned by his or her spouse.

The House version of the social security bill does not contain the dollar offset provision. It, along with other items in the complicated legislation, must be ironed out by a joint Senate-House conference committee before it is sent to the President.

The language in the Senate report on the bill (outlined here Nov. 11) is chilling for federal workers who had income by drawing dependent benefits if their spouse is entitled to a so-planned on boosting their retirementcial security pension. It reads like this:

"The committee bill would reduce benefits payable under social security to dependent spouses - including surviving spouses - by the amount of any civil services (federal, state or local) retirement benefit payable to the spouse. The provision would apply only to individuals applying for spouses' social security benefits in the future and only if the dependent spouse had a civil service pension based on his or her own earnings in public employment which was not covered under the social security system."

That means that IF the bill becomes law, federal employees retiring after the effective date of the law could not draw full dependent benefits based on their husband or wife's social security. The amount they could get would be reduced - "offset" is the term the Senate uses - by the amount of their civil service, postal, state or local government annuity.

At one point the Senate thought about writing guidelines that would establish a dependency test, so that some retirees might qualify for full social security dependent benefits, but rejected the idea, it said, because the test would be "subject to manipulation" and because of "administrative difficulites" involved in deciding who was, and who was not, dependent.

"For example," the Senate report says, "a government employee with earnings higher than those of his wife could qualify for a social security spouse's benefit by allowing a "few months to intervene between the date of his retirement and the effective date of his pension."

During the gap time, the Senate decided, a retiree could qualify as a "dependent" of his wife, become eligible for her social security dependent benefit and then start drawing his civil service annuity.

"Also," the Senate report says, "a dependency test could deny spouses' benefits in situations where it would seem undesireable to deny such benefits. For example, a woman might, in fact, be dependent upon her husband for most of her life and might have earned little or nothing in the way of retirement income protection in her own right, and yet be denied benefits if a dependency test were implemented. This could occur if her husband became ill shortly before reaching retirement age, thus forcing a temporary reversal of their usual dependency situation . . ."

The House version of the social security bill, as pointed out Friday, does not address the issue of dependency, or have the "offset" Penalty formula of the Senate bill. (Incidentally, the offset provision in the Senate bill would become effective "with respect to benefits payable for months starting with the month of enactment on the basis of applications filed in or after the month of enactment").

It is impossible to predict whether the conferees will accept the Senate language providing for offset, or ignore the offset idea as does the House bill. But they will have to do something before sending the measure back to the Senate and House for final approval. Insiders say the Carter administration reluctantly favors the offset provision, which would save the social security system an estimated $190 million a year by denying full dependent benefits to government retirees.

Secretary-Typist: Coastal Zone Commission has a Grade 5 opening. Call 634-6791 for details.

$10,000 Award: Joseph Botbol and Roger W. Bowen, both scientists for the U.S. Geological Survey, will split the before-taxes award for devising a computer information system. Officials say it will save the government $1.5 million in the first year. The $10,000 prize is the largest ever given out by USGS.

Computer Systems Analyst: D.C. Government has a Grade 13 opening. Call Mr. Nilsen at 727-1300.

Federal Correspondents Association: The FCA breakfast meeting with Rep. Edward Derwinski (R-Ill.) will be Tuesday, Nov. 22, at the National Press Club. I got the day right, but the week wrong in Friday's item about the session.