The budget agreement announced Sunday reaches deep into programs long cherished by members of Congress, social workers and millions of Americans, young and old. If it is approved, almost everyone would take a hit, and while some hits will be harder than others, all of them will hurt.

Under the agreement, the U.S. Postal Service in the next five years will be asked to absorb $5.38 billion in employee and health care benefits now paid by the government. Student loan defaults would be slashed by $2 billion during the same period.

Medicare would take the biggest single non-military spending cut. The health insurance program for 33 million aged and disabled Social Security recipients would be reduced by $4.9 billion in fiscal 1991 and $60 billion over the next five years.

And projected farm subsidies would be cut by $13 billion over the next five years. Compliance could mean a major structural change in the way government oversees the welfare of U.S. agriculture.

These four programs are key elements in the government spending side of the budget equation. In all, cuts in government benefits are expected to save $104.8 billion over five years. The rest of the $500 billion deficit-reduction package was expected to come from tax increases and cuts in military spending.

For the Postal Service, the budget agreement would mean picking up $689 million this year and $5.38 billion over the next five years in benefit and health care premium costs.

The new obligations, Postmaster General Anthony M. Frank said, will nearly wipe out $700 million in expected productivity gains this year. "This is pretty discouraging to our people," he added.

Frank criticized the budget proposal as a hidden "stamp tax," predicting that the post office's new summit-induced costs would cause postage rates to go up "five cents higher in 1995 than they otherwise would have been." The post office already has sought to raise the cost of mailing a first-class letter from 25 cents to 30 cents next year.

In the administration of student loans, the budget agreement envisioned reducing defaults by $2 billion over five years. The administration had projected that defaults would reach $2.3 billion in the fiscal year just ended, and $2.6 billion in 1991.

Provisions of the pact suggest restricting borrowing among students at proprietary trade schools and, to a lesser extent, community colleges and historically black colleges.

Some education advocates raised questions about the impact on opportunities for poor and high-risk students. One suggested change would bar schools with high default rates from student loan programs. Other proposals could eliminate correspondence schools and students without a high school diploma or the equivalent.

Another proposal would require credit checks on students 21 or older before they could receive a student loan: "We are only going to make these loans available to people who don't need the guarantee. Then why have the program?" said Stephen A. Blair, president of the National Association of Trade and Technical Schools.

In Medicare and Medicaid, the budget agreement made recommendations on how savings could be achieved, but spokesmen for authorizing committees said they will be the ones making the changes.

The agreement suggested that almost half the $60 billion in cuts would come from three major changes in charges to Medicare patients. The doctor-insurance deductible -- the amount a patient pays each year before Medicare starts paying the bills -- would rise from the current $75 a year to $100 in 1991, $125 in 1992 and $150 thereafter.

Also, Medicare patients would have to pay 20 percent of the cost of clinical laboratory tests. Finally, the premium for Part B of Medicare would rise from $28.60 per month to about $35 in 1991.

Rep. Fortney H. "Pete" Stark (D-Calif.), chairman of the House Ways and Means subcommittee on health, called the cuts "obscene," and said he would offer an alternative plan, "hitting rich people of all ages."

The rest of the $60 billion would come from cutting payment rates to hospitals, doctors, producers of durable medical equipment and others who care for Medicare beneficiaries. The document suggests raising Medicare payment rates to hospitals 4.1 percent in fiscal 1991, less than the 5.3 percent needed to keep pace with inflation.

Reimbursements to hospitals for the costs of capital investments would be cut by 15 percent, extra payments for use of interns and residents would be cut as would rates paid to doctors in radiology, anesthesiology and procedures Medicare deems to be overpriced.

In Medicaid, the federal-state welfare program for the poor, the budget agreement suggested a major new program to save $1.6 billion over five years for outpatient prescription drugs. Manufacturers could only charge a state Medicaid program the lowest price for drugs given any bulk purchaser in the state.

The summit document also suggested states be permitted to pay for the health insurance premiums of family members when a worker has employer-provided health insurance only for himself. Projected savings are $1 billion over five years.

Despite the magnitude of the Medicare-Medicaid cuts, the budget agreement asks that the programs simply be trimmed. For farm legislators, however, the required cuts are likely to mean major structural revisions in the decades-old crop subsidies paid for cotton, wheat, corn, rice and other grains.

Senate and House conferees drafting the joint 1990 farm bill were scheduled to meet today for preliminary discussion on the budget cuts and how to make them. The farm bill will define the government's role in U.S. agriculture for the next five years.

The conference is working with savings suggestions prepared for the summit by the Office of Management and Budget, but House Agriculture Committee Chairman Rep. E. "Kika" de la Garza (D-Tex.) said lawmakers would "look at everything."

"I've said all along that if they {the summit} give us the number, we'll be the ones to fill in the blanks," de la Garza said. "I've talked with the {House} leadership, and they're of the same opinion."

The Senate and House two months ago passed their respective versions of the farm bill, envisioning program benefits calculated at $53 billion to $55 billion spread over the five-year life of the bill.

Even then, however, legislators from both parties agreed the budget agreement would require significant cuts in benefits, especially the crop subsidies that are the core of any farm bill. The final summit figure -- $13 billion in cuts over five years, $1.3 billion in the first year -- was seen as high, but not altogether unexpected.

"I don't think anyone was blindsided," said Charles Connor, minority staff director for the Senate Agriculture Committee. "We {Republicans} were prepared for that; the range that we always used was $11-to-$13 billion."

Still, the size of the cuts rendered obsolete much of last summer's arcane debate on how to fine-tune subsidies. Under last weekend's deficit guidelines, subsidies are going to be hit with a hammer: "If you have to revise the policy to get money, that's a structural change," de la Garza said.

After what Connor called "nickel and diming" the subsidy program, the conference committee has two basic options for removing the lion's share of $13 billion from farm spending: lower the subsidized prices paid to farmers for their crops; shrink the acreage eligible for farm benefits.

Lowering subsidy levels -- so-called "target prices" -- would continue a practice begun under the old 1985 farm bill but abandoned in the legislation currently before the conferees. Shrinking eligible acreage under a program known as the "triple base option," however, has never been tried.

"There really are only those two choices, and they're both in the commodity programs," said Rep. Jim Jontz (D-Ind.). "Those are the payments that come directly out of farmers' pockets."

Jontz, de la Garza and other Democrats had sharp words for a program of cuts that appeared to reinforce the Bush administration's desire to emphasize free trade practices and take the government out of farm spending alogether.

"We play by the rules, and we will give them their cuts," de la Garza said. "Their {the administration's} intent is to change the structure of the programs. They couldn't do it with a frontal attack, so they wanted to use the budget summit."

Staff writers Dana Priest and Kenneth J. Cooper contributed to this report.

Smokers: Would pay 4 cents more per pack beginning Jan. 1 and an additional 4 cents in 1993.

Drinkers of: BEER -- Would pay 16 cents more per six-pack beginning Jan. 1. WINE -- Would pay 22 cents more per 750-milliliter bottle of table wine. LIQUOR -- Would typically pay 24 cents more on a 750-milliliter bottle of distilled spirits beginning Jan. 1.

Consumers of luxury items: Would pay a 10 percent tax on the portion of the purchase price that exceeds $30,000 for a car, $100,000 for a yacht and $5,000 for jewelry and furs beginning Jan. 1.

Taxpayers with incomes of $100,000 or more: Would lose a portion of their itemized deductions, with the reduction increasing as income rises.

Taxpayers making between $51,300 and $73,000 per year in wages or self-employment income: Would pay an additional 1.45 percent on their earnings over $51,300. The FICA payroll tax has two components, one for Social Security and one for Medicare. Currently, neither is assessed on income that exceeds a wage base of $51,300. The agreement would increase the wage base on the Medicare component to $73,000. This would be effective Jan. 1.

State and local government employees not already subject to the Medicare payroll tax: Would have to pay the tax beginning Jan. 1, 1992.