The House Energy and Commerce subcommittee on health voted yesterday to make Medicare pay for outpatient prescription drugs for the elderly and disabled after a beneficiary's out-of-pocket cost exceeds $400 a year.

The benefit, sponsored by subcommittee Chairman Henry A. Waxman (D-Calif.) and approved 8 to 6 along party lines, was added to the "catastrophic" health insurance bill for Medicare beneficiaries approved by the House Ways and Means Committee.

Advocates for the aged had pleaded for enlarging the benefits in the Ways and Means bill. The bill still contains no provision for the cost of long-term nursing-home care.

The monthly Medicare premium, $17.90, will rise to $22 next year to help cover the rising cost of the program. The amended House bill eventually would raise it an additional $5. Beneficiaries also would pay an 8 percent premium, not to exceed $580, on adjusted gross income of more than $6,000.

Rep. Edward R. Madigan (R-Ill.) warned that "the limits of federal spending are not without bounds." But Rep. Ron Wyden (D-Ore.) said, "For the last six years, Medicare and Medicaid have been under the knife."

The Ways and Means Committee has primary jurisdiction over Medicare hospital benefits. Waxman's subcommittee shares jurisdiction over the doctor-insurance part of the program and also handles Medicaid.

Also yesterday, the Waxman subcommittee adopted, 9 to 4, an amendment by Rep. Doug Walgren (D-Pa.) providing up to 120 hours a year of Medicare-paid, in-home services by home health agencies as a temporary respite for relatives and friends caring for frail elderly people.

By voice vote, the subcommittee adopted a Waxman amendment to prevent a nursing-home patient's spouse from being impoverished before Medicaid will pay for the care. In many cases where the patient has been the only source of income, most of the family income can be used up each month before Medicaid kicks in.

Under the Waxman provision, joint property and income would be split when one spouse goes into a nursing home. The patient also could turn over enough property and income to raise his or her spouse's assets to $12,000 and income to $925 a month. The money transferred would not be counted as part of the patient's assets or income in determining Medicaid eligibility.

Another Waxman amendment would require state Medicaid programs to pay all the premiums, copayments and deductibles under Medicare for aged and disabled welfare clients living below the poverty line. This would assure them complete Medicare coverage, including that for catastrophic illness.

The combined impact of the Ways and Means basic bill and the Waxman subcommittee amendments would guarantee that a Medicare beneficiary would:Receive as many as 365 days of free hospital care a year after payment of an initial $540 deductible. Pay no more than $1,700 a year out of pocket for all Medicare-covered costs, except outpatient prescription drugs. Pay no more than $400 a year out of pocket for outpatient prescription drugs. Receive improved home health, skilled nursing facility, hospice and mental health services.

The amended bill would raise premiums $1 a month for general benefit improvements, $3.60 for the drug provision and 40 cents for the home-respite care. The increases would come over several years.