Oct. 29 (Bloomberg) -- Health-care legislation released today by House Democrats would cut the federal budget deficit by $104 billion over the next 10 years, the Congressional Budget Office said.

The measure would “slightly reduce” the deficit in the subsequent decade, the nonpartisan agency said.

The bill analysis by the CBO said the legislation would increase the share of Americans with health insurance to 96 percent from the current 83 percent. The bill would leave 18 million people without insurance, about one-third of whom would be illegal immigrants, CBO said today.

The CBO assessment may ease concerns about the cost of the legislation. President Barack Obama has said he will not sign a health-care overhaul bill that adds “one dime” to the deficit.

The agency cautioned that the plan’s price tag might prove much higher if lawmakers don’t stick to their cost-savings plans, which it said could be difficult.

“These longer-term projections assume that the provisions of H.R. 3962 are enacted and remain unchanged throughout the next two decades, which is often not the case for major legislation,” the CBO said. “The bill would put into effect (or leave in effect) a number of procedures that might be difficult to maintain over a long period of time.”

As an example, the agency said the bill would leave in place a scheduled 21 percent cut next year in Medicare reimbursements to doctors, something lawmakers said they plan to repeal.

“The long-term budgetary impact of H.R. 3962 could be quite different” if this and other provisions generating savings “were ultimately changed or not fully implemented,” the CBO said.

To contact the reporter on this story: Brian Faler in Washington at bfaler@bloomberg.net

Last Updated: October 29, 2009 17:26 EDT