Uncle Sam's company health program, which covers 9.2 million people, including half the residents of the Washington area, costs employes more and covers less than similar programs offered workers by some states and private firms.

That, according to the House Post Office-Civil Service Committee, is the conclusion of a six-month long ($90,000) study made for it by William M. Mercer Inc., an employe benefit consultant.

The committee, which has been feuding with the Office of Personnel Management over OPM's handling of the $5 billion program, begins subcommittee hearings July 27. The vehicle for the hearings is the Mercer Report; the purpose is to hamstring OPM Director Donald Devine's authority over the Federal Employes Health Benefits program.

Premiums paid by workers jumped an average of 30 percent last year, while benefits were cut back anywhere from 12 percent to 16 percent. Those are about the only points that warring factions agree on as they try to lay the blame for the condition of the government health program.

Many Democratic congressmen and union leaders see Devine as a political tyrant who made changes in the FEHB--like attempting to end payments for nonemergency abortions--for philosophical reasons and tried to cut costs by trimming bona fide health protection for government workers and their families.

Devine and company say the FEHB is a mess because certain health plans in the past were allowed unwisely to boost benefits and hold down costs for political reasons. They say the bill came due last year, and OPM chopped benefits for 1982 to avoid even higher premium increases that are partly passed on to taxpayers.

Mercer's report covers the six big government plans (Blue Cross-Blue Shield, Aetna, two Kaiser of California plans and two postal union plans, APWU and NALC.)

It matched benefits against those of state employes (Maryland, Michigan, California, Illinois, New York, Pennsylvania, Texas and Wisconsin) and major firms such as AT&T, Citibank, IBM and GTE.

Rep. Mary Rose Oakar (D-Ohio) will kick off the hearings before her Compensation and Employe Benefits subcommittee of the PO-CS Committee. Her goal, an aide said, is to come up with legislation that will put the FEHB on sound financial ground, increase congressional oversight over the program and guarantee that employes pay only what is fair for the best coverage available.

The FEHB consists of more than 120 plans, ranging from large government-wide carriers to local health maintenance organizations and union-backed plans.

Most federal employes are in Blue Cross-Blue Shield. Those who elect its high option self and family coverage now pay $41.77 every two weeks in premiums. The government pays an additional $39.93. Low option family coverage is $10.53 biweekly for employes. Government pays $31.58.

Mercer's detailed (208 page) report says that many private and state government workers get better coverage with lower premiums, or have their entire premium paid by the employer.

Toward the end of the year federal and postal employes will have an open season enrollment period when they can select new health insurance coverage for the 1983 year.

Full committee chairman Bill Ford (D-Mich) is anxious to ensure that this year's insurance flap that left workers locked into higher-cost health plans for seven months is not repeated next year, or ever again.

After all sides--insurance experts, unions, federal officials and legislators--have had their say, the committee hopes to come up with legislation to: make benefits more uniform, guarantee open seasons before rates go up (or benefits go down) and give workers a plan that doesn't cost nonfederal employe taxpayers an arm and a leg.

If the government health program is liberalized (to pay more or all of the premium) that would have an effect on the size of future pay raises should government switch to a "total compensation" system that measures the value of its pay, pension, insurance and fringe benefits package against those offered in industry.