Budget paring is likely to affect health-care plans. SOCIAL PROGRAMS AND DEFICIT

Almost ignored in the congressional rush to adjournment is the wide-ranging impact the new deficit-reduction law will have on United States health care. The effects appear strongest on the elderly. ``A mixed blessing,'' says Martin Corry, director of federal affairs of the American Association of Retired Persons (AARP). On the positive side: nursing homes will have to meet stiffer standards, which have been sought for years by reformers.

Also, physicians will now have an incentive to accept medicare payments as full payment for their services to the elderly, instead of billing individuals an additional amount.

On the negative side, from AARP's point of view: Older Americans will have to pay higher premiums to belong to that part of medicare that pays for physicians' services. It's a voluntary part of medicare, the program supposed to be the government's principal health aid to the elderly, and the overwhelming majority of elderly Americans do participate.

Another aspect of the measure could ultimately lead to immense change, if it sets a precedent.

It is a provision that this year loosens the rules of medicaid to provide coverage to thousands of pregnant women and their children, who now do not qualify for assistance because their family incomes, although very modest by most standards, are too far above the poverty income. Under the new bill they will qualify if their incomes are between 150 and 185 percent above the poverty line.

In recent months one of the major efforts of welfare reformers, and some advocates of the poor, has been to provide at least a portion of medicaid coverage to people on welfare who take jobs. The thinking behind such advocacy is that, for many mothers, this action would remove a major stumbling block to leaving the welfare rolls. The action taken on behalf of pregnant low-income women could lead to a move in this direction in the next Congress.

Overall the new law provides what Congress says will be $33.2 billion in savings this fiscal year, and $79 billion next year.

Of that amount, the Congressional Budget Office (CBO) estimates that slightly more than $2 billion will be in savings for this fiscal year (1988) in medicare, and about $3.5 billion next year.

At the same time, the CBO estimates the cost of medicaid will rise by $44 million this year, and by $209 million next year. Half of that cost is expected to be because of the program for poor pregnant women, and half to tighter nursing-home standards and the provision for more medical services for the homeless.

For many Americans who receive medicare benefits, the greatest impact of the new law will come from a premium they pay. It is for Part B, the optional section of medicare that more than 90 percent of Americans subscribe to. It pays physicians' fees. At present the monthly Part B premium is $17.90; for months it has been scheduled to rise to $24.80 on Jan. 1.

The new law indirectly requires the premium to be higher in 1989, but opinions differ as to how high. That's because the law talks in terms of percentages, as past laws have also, not dollar amounts. The measure says that next year 25 percent of the nationwide costs of the Part B section should be paid by the elderly themselves in the monthly form of premiums, the same percent paid now.

No one knows how much that 1989 premium will be, largely because no one is sure what how much the cost of medical care will have risen by 1989.

The CBO estimates the 1989 monthly increase at only about $2, bringing the monthly total to $26.80. The Democratic Study Group is less sanguine and puts the figure at $33. ``We've had numbers all over the map'' estimating the 1989 monthly premiums, says the AARP's Mr. Corry.