SAN JOSE, Calif. _ The raucous debate over the Medicare bill overshadowed a provision that could change how -- and how much -- some Americans pay for health care.

The Medicare reform bill will allow employers to create tax-exempt "Health Savings Accounts" that workers will be able to tap to pay medical expenses. That means qualifying employees will have access to tax-sheltered accounts for three of life's biggest bills: retirement, college tuition and medical care. However, only those employees enrolled in company-sponsored health plans with high deductibles can open the accounts.

President Bush is expected to sign the legislation, which passed the Senate last Tuesday and the House the previous week.

Loosely akin to a medical 401(k), the Health Savings Accounts will appeal to many workers. The so-called HSAs can build from year to year as employers and employees contribute money. Workers can take the money with them if they change jobs.

The accounts may be used to pay for everything from doctor's visits and drug prescriptions to chiropractic care and premiums for long-term-care insurance. Cash-strapped workers can even tap their HSA for non-medical expenses but they must pay a 10 percent penalty on the amount withdrawn.

Experts predict such accounts could slow spiraling health-care costs by encouraging workers to conserve on medical care because they'll be paying some bills themselves.

"It gives the individual the right incentives to be a wise consumer," said Devon M. Herrick, a senior fellow with the National Center for Policy Analysis in Dallas . "It allows you to make those decisions about which doctors to see, which appointments are worth the money and you'd have trade-offs _ 'Do I get the Claritin over the counter or the Allegra that costs $60?'"

This isn't the first attempt at tax-sheltered medical accounts. Many employers already offer workers an alphabet soup of such plans, including Medical Savings Accounts (MSAs), Flexible Spending Accounts (FSAs) and Health Reimbursement Accounts (HRAs).

But each of those programs come with hobbling restrictions. For example, MSAs are available only to small companies or the self-employed. Many workers shy away from FSAs because they must forfeit any money they don't spend by year's end. Money in HRAs can be carried forward from year to year, but workers can't take the cash with them if they quit or are fired.

The new accounts, in contrast, will be available to employers of all sizes, and the money in the accounts will belong to the worker _ and could even be stashed away to pay for medical bills in retirement.

Not all workers will be eligible, however. To qualify, workers must be enrolled in "high-deductible" insurance plans that require workers to pay at least the first $1,000 of medical expenses themselves before the insurance begins to pick up the tab.

Such plans allow workers and their employers to pay sharply lower premiums _ and plow the savings into an HSA "rather than give that money to the insurance company month after month after month," said Michael Berry, who heads American Health Value, which administers MSAs in Boise , Idaho .

Under the new Medicare bill, workers or their employers could fund HSAs with the amount of the deductible, not to exceed $2,250 for an individual and $4,500 for family coverage. Starting in 2006, workers who are 55 and older would be allowed to contribute at least $500 extra.

Barry Miller, a consulting actuary with Segal Co. in Los Angeles , predicts the bill has "the potential to be landmark legislation." Fortune 500 companies with flexible benefits plans might add the HSA to their menus. And smaller companies may be drawn by the sharply lower premiums under high-deductible plans.

Still, he warns, companies that already provide health plans could find that their healthiest workers could jump for the HSAs. If that happened, premiums for the remaining work force could jump _ and wipe out the savings.

Adoption of the programs could be slow at first, experts warn, as it will take time for insurance carriers to design attractive packages.