DALLAS - When Robert Barnhouse of Richardson, Texas, lost his job in October, he tried to hold onto his health insurance but quickly found he couldn't afford the $500 monthly premiums.

The 61-year-old engineer dropped the coverage after one month and is now taking his chances. "I'm paying more attention to my diet and exercising more, because I can't get sick,'' he said.

So far, he's avoided any major health-care expenses, but without insurance, he's had to postpone the exam and blood tests he schedules at the beginning of each year.

Barnhouse is one of 5.1 million uninsured Americans between 55 and 64 who, experts say, would benefit from a proposal to let people in late middle age buy into Medicare early.

Medicare kicks in at 65 for most Americans., but an early buy-in would allow someone as young as 55 to enroll in the program and pay a higher monthly premium than seniors do.

Depending on how lawmakers design the program, the premiums would cost several hundred dollars a month. The services would be the same as those for current Medicare beneficiaries.

The idea has been around for years, but it has gained new currency as the recession deepens and a Democrat-run Congress and White House begin to discuss health-care reform.

Advocates of an early Medicare buy-in say it would complement other entitlement reforms because it would keep older workers healthy and productive longer and help rein in government spending over the long haul.

"The proposal has legs for the first time in years,'' said Stuart Guterman, a policy analyst at the Commonwealth Fund, a private foundation that researches health care issues.

"Suddenly, the notion of buying into Medicare has friends in high places,'' he said.

Senate Finance Committee Chairman Max Baucus' health- care plan, which many experts view as the starting point for reform in the new Congress, has called for lawmakers to make the buy-in immediately available.

The option would remain in place, Baucus said, until Washington comes up with a more comprehensive answer for the 46 million Americans without insurance.

The incoming deputy director of the White House Office of Health Reform, University of Texas associate professor Jeanne Lambrew, also has spoken favorably of an early buy-in.

"The political opponents to a Medicare buy-in have been successful for the last decade, primarily on ideological grounds,"  she told the Senate Aging Committee last year, "but concerns about ideology may be outpaced by concerns about health security as the pressure for change rises.''

Opening Medicare to Americans in their late 50s or early 60s could plug a gaping hole in the nation's health-care safety net, experts say.

Between 2000 and 2010, as the oldest Baby Boomers approach or reach retirement, the number of Americans 55 to 64 will increase 50 percent, from 24.4 million to 36.2 million.

DALLAS - When Robert Barnhouse of Richardson, Texas, lost his job in October, he tried to hold onto his health insurance but quickly found he couldn't afford the $500 monthly premiums.

The 61-year-old engineer dropped the coverage after one month and is now taking his chances. "I'm paying more attention to my diet and exercising more, because I can't get sick,'' he said.

So far, he's avoided any major health-care expenses, but without insurance, he's had to postpone the exam and blood tests he schedules at the beginning of each year.

Barnhouse is one of 5.1 million uninsured Americans between 55 and 64 who, experts say, would benefit from a proposal to let people in late middle age buy into Medicare early.

Medicare kicks in at 65 for most Americans., but an early buy-in would allow someone as young as 55 to enroll in the program and pay a higher monthly premium than seniors do.

Depending on how lawmakers design the program, the premiums would cost several hundred dollars a month. The services would be the same as those for current Medicare beneficiaries.

The idea has been around for years, but it has gained new currency as the recession deepens and a Democrat-run Congress and White House begin to discuss health-care reform.

Advocates of an early Medicare buy-in say it would complement other entitlement reforms because it would keep older workers healthy and productive longer and help rein in government spending over the long haul.

"The proposal has legs for the first time in years,'' said Stuart Guterman, a policy analyst at the Commonwealth Fund, a private foundation that researches health care issues.

"Suddenly, the notion of buying into Medicare has friends in high places,'' he said.

Senate Finance Committee Chairman Max Baucus' health- care plan, which many experts view as the starting point for reform in the new Congress, has called for lawmakers to make the buy-in immediately available.

The option would remain in place, Baucus said, until Washington comes up with a more comprehensive answer for the 46 million Americans without insurance.

The incoming deputy director of the White House Office of Health Reform, University of Texas associate professor Jeanne Lambrew, also has spoken favorably of an early buy-in.

"The political opponents to a Medicare buy-in have been successful for the last decade, primarily on ideological grounds,"  she told the Senate Aging Committee last year, "but concerns about ideology may be outpaced by concerns about health security as the pressure for change rises.''

Opening Medicare to Americans in their late 50s or early 60s could plug a gaping hole in the nation's health-care safety net, experts say.

Between 2000 and 2010, as the oldest Baby Boomers approach or reach retirement, the number of Americans 55 to 64 will increase 50 percent, from 24.4 million to 36.2 million.

At a time of life when serious or chronic health problems frequently crop up, many Boomers are losing their group insurance, said John Sheils, a senior vice president of the Lewin Group, a health-care consulting firm.

The recession has cost many their jobs and employer-subsidized medical coverage. Often, they take part-time jobs or go to work for businesses that don't offer group health plans, he said.

Likewise, early retirees once could depend on employer-subsidized insurance, but companies hit by rising medical costs have scaled back their retiree health coverage, Sheils said.

People in late middle age who turn to individual insurance might suffer sticker shock or worse, said Richard Johnson, an economist with the Urban Institute, a public policy research group.

The annual premium for people 60 to 64 averages more than $5,000 for single coverage and $9,200 for family coverage, according to the Baucus health care report.

"Many with health problems are denied insurance or offered policies that exclude coverage for pre-existing conditions,'' Johnson said.

Despite advocates' claims that premiums alone would cover the cost of a Medicare buy-in program, others believe taxpayer subsidies would be needed to make the option affordable for most people.

The proposal poses a dilemma for policymakers, said James Capretta, a fellow at the Ethics and Public Policy Center. If lawmakers don't subsidize an early buy-in, the substantial premium would appeal only to people who can't buy insurance in the private market because of health problems, he said.

"It would end up helping only a limited number of Americans,'' Capretta said.

However, if lawmakers subsidize the program enough to drive down premium costs, they might cause a stampede of people leaving private insurance and encourage more Americans to retire early, he said.

"That would be counter-productive,'' Capretta said. "Our government's already overburdened with Social Security and Medicare obligations and ought to be persuading people to delay retirement.''

A taxpayer subsidy would only exacerbate Medicare's financing problems, said John Goodman, president and chief executive of the Dallas-based National Center for Policy Analysis.

"Instead of expanding another government entitlement, we should be giving employers more ways to help retirees obtain and afford individually owned insurance,'' he said.

Still, advocates of an early Medicare buy-in say critics overlook long-term savings that advocates assert the government would reap.

"Opening Medicare to Americans in their late 50s or early 60s would help prevent serious health conditions from deteriorating and resulting in higher costs to Medicare once those people turn 65,'' Guterman said.

Research has found that previously uninsured adults with common chronic illnesses spend more on doctors' visits and hospital stays after they become eligible for Medicare than people who had insurance before 65, he said.

"People who are uninsured wait until they can get Medicare, so there's a pent-up need at 65,'' Guterman said. "If they received treatment earlier, they'd be healthier and cost Medicare less.''