WASHINGTON - A majority of senators voted against including a new government plan to help elderly and disabled people avoid nursing homes as part of the health-care overhaul, but the program is likely to become law anyway.

The so-called CLASS plan would allow workers to sign up for a payroll deduction program similar to Social Security that would provide in-home assistance when they are older or disabled.

Participation would be voluntary, with fees and benefits to be determined on an actuarial basis. As with Social Security, workers' contributions would fund the benefits of contemporary retirees.

Despite widespread concern about the potential effect on the federal deficit, the plan survived in the Senate bill; although an amendment to delete it attracted a majority, it fell short of the 60 votes needed. The plan was approved by the House in its bill.

Now its fate depends on the congressional leaders who must reconcile the varied provisions of the two huge bills, but the plan is getting strong support from groups representing seniors and the disabled - two potent lobbies.

"It's one of the few transformational things in the health-care bill," said Larry Minnix, chief executive of the American Association of Homes and Services for the Aging, a Washington advocacy group. "It gives everybody the opportunity to begin to plan for an eventuality everybody will face."

Those who pay into the plan would have to wait at least five years before they could receive benefits and would have to be employed to be eligible to pay in. The program would accept those with preexisting conditions, something private insurers that sell long-term-care policies balk at.

"By the time you know you need long-term care," Minnix said, "it's often too late and too expensive."

The plan, he added, will help ease the strain on Medicaid, which now covers much of the cost of caring for the disabled and elderly.

The measure's survival is a product of timing, good luck, and the legacy of the late Sen. Edward M. Kennedy (D., Mass.), who long championed such a program.

But critics still contend it creates a new government entitlement that could overwhelm the already beleaguered federal coffers. The problem, they say, is that fewer people are likely to pay into the system than projected, resulting in benefits outpacing revenues.

"The program simply is not viable," said Robert Zirkelbach, spokesman for America's Health Insurance Plans, an industry trade group that opposed the measure.

Zirkelbach and other critics point to a study by the nonpartisan Centers for Medicare and Medicaid, which suggests the program will stop paying for itself by 2025 and then begin to run a deficit.

A Senate requirement that the program be self-sustainable means premiums will have to be set high enough to cover the cost of the benefits, which are likely to be as high as $75 a day. Premiums could run as high as $240 a month, CMS said, an amount that could keep many younger, healthier people from signing up.

With fewer young, healthy workers participating, premiums could go even higher and cause the program to enter a "death spiral," the study argued.

"Premiums are going to be exceptionally high," said Steve Schoonveld of the American Academy of Actuaries. Congress, he said, "has to decide if this is a social program or an insurance program and not somewhere in between."

But the nonpartisan Congressional Budget Office is more optimistic, projecting cheaper premiums and forecasting that the program is likely to remain fiscally solvent over 75 years.

And while a benefit of $50 to $75 a day might not sound like much, Minnix said it could make the difference between being able to stay with a family member or being sent to a nursing home or assisted-living facility.

"You live with your daughter. Your daughter has to work. What does $75 a day buy?" he said. "It all of the sudden buys you someone to come in and stay with you six to eight hours a day while she works."