Congress moved yesterday toward final approval of legislation allowing disabled Americans to keep their government-financed health benefits when they take jobs, removing a major obstacle they face when attempting to join the work force.

Advocates said the rare piece of bipartisan legislation could lead to the employment of large numbers of people with disabilities.

Under current law, recipients of Social Security disability and related benefits lose their government-funded health coverage if they take jobs.

The proposed law would allow disabled people to keep Medicare benefits longer than currently allowed and would let them buy into the Medicaid program. It would also break new ground by creating a demonstration project under which states could extend Medicaid coverage to people who have degenerative conditions but are not yet disabled, such as those with Parkinson's disease, multiple sclerosis and AIDS.

"This is the first major attempt by Congress to address the pervasive disincentives to work that have existed in the Social Security disability programs for decades," said Andrew Sperling, director of public policy at the National Alliance for the Mentally Ill. "Despite the image that nothing gets done in Washington, this is a testament to what bipartisan cooperation can achieve."

After weeks of haggling over how to pay for the bill's estimated cost of up to $800 million over five years, House and Senate negotiators agreed Wednesday night on language resolving relatively minor differences between different versions passed earlier by both houses. The measure was then attached to a bill extending expiring tax breaks, which was approved by the House 418 to 2 last night.

Sponsors of the measure said they are confident the Senate will pass it before Congress adjourns for the year, and President Clinton has indicated that he will sign the bill.

The work incentives bill was hailed by outside advocates as well as congressional sponsors as the most important legislative advance for the disabled since the passage of protections for their civil rights in the Americans With Disabilities Act nine years ago.

The bill was the product of three years of legislative spadework by Sens. James M. Jeffords (R-Vt.) and Edward M. Kennedy (D-Mass.) and a wide array of other lawmakers who rarely agree on anything.

Gradually, most lawmakers fell in line behind the bill, despite misgivings among conservatives over some provisions that they viewed as an invitation to an expansion of Medicare and Medicaid. Leaders of both parties championed the disabilities bill as evidence of both compassion and commitment to the work ethic.

"Government should be helping people to work, not building barriers to independence and freedom," said House Ways and Means Committee Chairman Bill Archer (R-Tex.). "This bill will tear down those barriers."

According to congressional estimates, there are as many as 8 million working-age adults who receive disability benefits, many of whom could take jobs if they could keep their government health benefits. A national survey earlier this year showed that, while 76 percent of people with disabilities wanted to work, nearly 75 percent are unemployed.

Disability groups have estimated that about 2 million of the 8 million would immediately forgo disability payments and take jobs after the bill is passed, according to a Kennedy aide.

The estimated cost of the new program would be recouped if only 70,000 people did so, another aide said. If 210,000 of them took jobs, the government could save $1 billion annually in disability payments, the aide said.

As approved by negotiators, the bill would allow disability beneficiaries who take jobs to receive Medicare benefits for 8 1/2 years, compared with four years under current law. It would also enable those with annual incomes of less than $75,000 to buy into Medicaid under guidelines that protect low-income people.

Funding for the pilot project allowing Medicaid payments to help people stave off disability from degenerative diseases was among the last issues to be settled. As part of last-minute bargaining over the budget, the administration won an extra $100 million for the program, boosting its total five-year cost to $250 million.

The cost of the bill will be defrayed by savings in other areas, including student loans, tax breaks for foster care and the speed-up of certain state payments to the federal government.