A coalition of groups representing the elderly and disabled is gearing up to battle provisions in the deficit-reduction plan that would cut $60 billion from Medicare over five years.

Their aim, spokesmen said, is not to kill the whole budget agreement, but to soften cuts in Medicare benefits and to protect the poor and near-poor among Medicare's 33 million beneficiaries from the financial impact.

John Rother, legislative director of the American Association of Retired Persons, which claims 32 million members, said, "We have always recognized that seniors, like everyone else, must make a contribution. What we're insisting on is that those who cannot afford to sacrifice further be protected."

Last year the fury of many elderly Americans at a mandatory Medicare fee of up to $800 a year forced repeal of the 1988 Medicare catastrophic-illness insurance law. But one vote-counter said observers should not assume the elderly could succeed in killing the summit agreement by themselves if they do not get the Medicare changes they want. The catastrophic fee issue affected only Medicare enrollees, so their objections were pivotal. This time, he said, the summit deal affects all of society, "and nobody is in for a hit of $800."

Representatives of 30 organizations met this week under the leadership of Arthur Flemming, who heads SOS, a coalition of pro-Social Security groups, and vowed a strong legislative battle to alter the Medicare cuts.

Among groups reported present were the AARP, Families USA, National Council of Senior Citizens, National Council on Aging, Older Women's League and Gray Panthers.

Ron Pollack of Families USA said some favored starting work immediately to bring down the whole budget package. But others, who ultimately prevailed, "felt cuts of some type were inevitable and we should work to modify them," another participant said.

Pollack said the consensus was to focus on two objectives: "Get the cuts in the Medicare benefits reduced as much as possible," and work for a requirement that the federal government pay all out-of-pocket Medicare fees, premiums and co-payments for Medicare beneficiaries with income less than 150 percent of the poverty line. Under existing law, the states must by 1992 pay all those costs for beneficiaries with incomes below the poverty line.

The coalition wants to alter summit plans that would increase the monthly Medicare premium from $28.60 a month to about $35 next year; require beneficiaries to pay 20 percent of clinical laboratory fees, and in the doctor-insurance portion of the program, require a beneficiary to pay the first $150 a year in bills before Medicare kicks in, instead of $75.