Murphy's Law if anything can go wrong it will) caught up with me in yesterday's "correction" of the 1986 health premiums to be charged by the Government Employees Hospital Association. The 1986 rate will increase 83 cents, to $10.75 per pay period for single coverage, and will go up $2.03 biweekly to $19.92 for family coverage.

Health insurance premiums paid by most federal workers will drop an average of about 6 percent next year, with some of the plans cutting premiums nearly in half, the Office of Personnel Management announced yesterday.

OPM said the companies in the nation's largest group health insurance program have agreed to the lower premiums because their reserves have grown as insurance utilization has declined. OPM negotiates with the carriers annually, and premium and benefit levels are based in part on the financial results of the previous year.

Insurance companies have been reporting in recent years that subscribers are more cautious about filing claims, in part because of cutbacks in coverage and requirements for seeking second medical opinions, and that subscribers are paying a bigger share of their medical bills. Some major companies reported a drop in claims of up to 20 percent in the past nine months.

In addition to the unprecedented across-the-board premium reduction by most of the major carriers, 11 of the 200 plans in the federal program will give refunds to subscribers, OPM said.

The action is almost certain to have an effect on the rest of the nation's health insurance industry, which has experienced a similar decline in utilization as benefits have been trimmed.

In the past, premium increases have gone into effect in private-sector insurance plans following increases in the federal program, and many of the cost-containment features of the federal insurance program have been adopted outside government.

About half the residents of the Washington area are covered by the U.S. government's Federal Employee Health Benefits Program. OPM officials said that annual premium cuts next year will range from $16 to more than $500, depending on the coverage subscribers choose during the open enrollment period, which will run from Nov. 4 to Dec. 6. Annual premiums now range from $300 to more than $1,800.

Nationwide, the federal program provides health insurance protection for more than 9 million civil servants and retirees and their relatives.

Yesterday, OPM Director Constance Horner said President Reagan's "cost-conscious leadership" has helped make the premium cuts possible. Horner said the government's contribution to health insurance premiums will also be cut next year, by upwards of $90 a family.

Premiums went up an average of 4 percent this year, the lowest annual increase in more than six years. But this is the first time in the 25 years that the federal health program has operated that most major plans cut premiums.

OPM said that among the largest insurers in this area planning refunds are Aetna, the American Federation of Government Employees, Government Employees Hospital Association and the National Association of Letter Carriers.

In May, the largest health insurer, Blue Cross-Blue Shield, announced plans to give rebates of $18 to $400 to the 1.4 million federal workers and retirees currently enrolled in its government plan. It said the refunds were made possible by declining costs because subscribers are not using insurance as often or are paying a bigger share of their medical bills.

The Reagan administration approved the refunds, but the payments will probably be delayed because of a class action challenge in court by persons covered by the health plan in 1983 and 1984. Those former subscribers claim that they should get a portion of the rebates intended for only current enrollees.

Two smaller nationwide plans -- Goverment Employees Benefit Association, which covers CIA personnel, and the Foreign Service health plan -- also plan to give refunds to current subscribers. Health plans covering U.S. workers in Idaho, Puerto Rico and Washington state also intend to give rebates.

Among the changes planned by major health plans here are:

Premiums for Blue Cross-Blue Shield's high-option one-person plan will decrease by 70 cents per biweekly pay period, and the high-option family premium will go down by $1.39. The standard premium for one person will drop 93 cents, and family coverage will cost $2.71 less.

Aetna's high-option single coverage will cost $5.11 less per pay period, and family coverage will be $8.86 lower. One-person standard premiums will drop 96 cents, and the family plan will go down $2.05 every two weeks.

The American Federation of Government Employees' high-option one-person premium will be trimmed by $7.32 per pay period, and family coverage, $15.47.

The American Postal Workers Union's family coverage will be cut $12.88 per pay period, and single policies will drop by $6.20.

The National Association of Government Employees' family plan will drop $17.05 biweekly, and the Rural Letter Carriers Plan family coverage will cost $20.03 less every two weeks.