Gary Ahlquist, a senior vice president at Booz-Allen & Hamilton, a management consulting firm, predicted that as costs increase, more employees will choose high-deductible insurance, with lower premiums.

The medical savings account system would allow them to buy low-cost, high-deductible insurance, which is not now readily available.

The plans let workers create tax-free savings accounts to use for medical costs, combined with lower-cost, high-deductible insurance to cover major medical care.

Supporters say the legislation would make the lower-cost, high-deductible insurance more attractive for millions of people with little or no coverage.

But managed-care companies say it would be unfair to give special tax breaks to people choosing high-deductible insurance.

The introduction of high-deductible insurance has increased demand for pricing information among consumers.

If those people enrolled in them and bought only the cheaper, high-deductible insurance policies, critics say, people remaining in traditional insurance plans would face higher rates.

Advocates argued that people who bought high-deductible insurance would be careful about demanding health care, because they would be paying with their own money.

President Bush has pointed out that consumers can buy relatively inexpensive, high-deductible insurance to protect against catastrophic illnesses and can pay for routine care with new tax-free health savings accounts.

The plans make the most sense for healthier and wealthier people because they require taking on a high-deductible medical insurance.