House Democrats would rely less on tobacco taxes than the Senate would and more on cuts to Medicare insurers to pay for a proposed $50 billion expansion of a children’s health insurance program.

The proposal, introduced late Tuesday, also would eliminate a 10 percent cut in the reimbursement rate for doctors who treat Medicare patients that is scheduled to take effect Jan. 1. Instead, the legislation would give doctors a 0.5 percent increase in their reimbursement rates each of the next two years when they treat Medicare patients.

Democrats would pay for the expansion of the State Children’s Health Insurance Program, or SCHIP, through a 45-cent increase in the federal excise tax on a pack of cigarettes and by lowering payments to many insurance plans participating in the Medicare Advantage program over the next four years.

The Senate bill would increase cigarette taxes by 61 cents a pack to pay for a smaller, $35 billion expansion, pushing overall spending over the next five years to $60 billion.

President Bush has indicated he would veto the Senate bill. The White House has recommended a $5 billion increase in the program.

"If he wants to veto health care for kids, historians will deal with that," said Rep. Pete Stark, D-Calif.

The 10-year-old program subsidizes the cost of insuring children living in families that earn too much to qualify for Medicaid but not enough to afford private insurance.

More than 6 million people, including about 600,000 adults, get health insurance coverage each year through SCHIP. The federal government pays for about 70 percent of the program and the states pay the rest.

The House bill is more than 900 pages long and deals with much more than SCHIP. It would eliminate cost-sharing for preventive services in Medicare, such as cancer screenings. In addition, it reduces the co-payment on mental health outpatient services from 50 percent to 20 percent.

The bill would also freeze reimbursement rates for some Medicare providers next year; namely, home health agencies, nursing homes and long-term care hospitals. Such hospitals typically care for patients with complex need who stay in the hospital for more than 25 days.

The overall cost of the bill is about $90 billion over five years.

Republican leaders made it clear that they believe the proposed expansion of SCHIP is too large.

"It will continue to increase taxpayer-funded coverage for adults and middle-class children and move the United States toward a system of completely government-controlled health care," said Rep. Jim McCrery of Louisiana, ranking Republican on the House Ways and Means Committee.

But Rep. John Dingell, D-Mich., said the Democrats’ bill would allow 5 million uninsured children to become insured. He denied that the proposal would expand eligibility for the program.

"We’re not proposing to cover adults, parents or wealthy children," said the chairman of the House Energy and Commerce Committee. "This is solely for children who are currently eligible for coverage under the program."

Rep. Frank Pallone, D-N.J, said the proposal was practical, not ideological. "These are working families that can’t get coverage on the job and can’t afford to pay for it in the private market," he said.

"In the long run, it’s going to save the health care system money," Pallone said. "This is very cheap. You can do it for about $3.50 per day per kid."

Democrats and the administration have sparred over how many children are uninsured and eligible for government-sponsored coverage.

The Congressional Budget Office weighed into that debate Tuesday by rejecting the numbers used by the Bush administration. The administration has pointed to a study from the Urban Institute, which said that only about 1.1 million currently uninsured children are eligible for Medicaid or SCHIP.

That compares with the estimate of 5 million to 6 million children cited in other studies. The CBO said it regards the latter estimates as more accurate. The numbers cited by the administration count only those children uninsured for an entire year, while substantial numbers of children are uninsured for just part of the year and could qualify for public coverage.

"The administration’s estimate understates the number of uninsured children who might participate in Medicaid or SCHIP," said the CBO’s director, Peter Orszag.