Broadly speaking, the legislation would revamp the way health insurance works. Insurance companies would face a slew of new government rules, dealing with everything from guaranteed coverage for people with health problems to possible limitations on profits.

Taxpayers, employers and individuals would share in the cost of expanding coverage to nearly 50 million uninsured Americans.

Under the bill, Americans would be able to buy long-term care insurance from the government for $65 a month.

Lawmakers at both ends of the Capitol are accelerating their drive to enact health care legislation, with House Democratic leaders also outlining a proposal. But Democrats are not saying yet how they plan to cover the costs, which could exceed $1 trillion over 10 years.

House Republican Leader John Boehner of Ohio warned Wednesday the Democrats' plans are a "bait and switch" that will lead to higher taxes, more government control and rationed care.

A first-ever tax on employer-provided health benefits figures prominently among financing options under consideration in Congress, but President Barack Obama campaigned against that last year, loudly criticized rival Sen. John McCain for backing it and its inclusion would require him to reverse course. Obama says health care legislation must be paid for, but his own list of tax increases and spending cuts doesn't cover the full cost.

Kennedy's long-term care plan is designed to help disabled people pay for support services that would allow them to remain in their own homes and avoid moving into nursing homes. People would enroll in the program during their working years and begin paying premiums. To collect benefits, a person would have had to pay premiums for at least five years.

The benefit would be modest — not less than $50 a day — but it could be used to cover a wide range of services. Premiums would average $65 a month, below the current cost of most private coverage for people in their 50s and 60s. For students and young workers, premiums would be as low as $5 a month.

Prospects for the long-term care provision are uncertain, but Kennedy's advocacy may sway other lawmakers. For Kennedy, who is being treated for brain cancer, health care legislation would be the crowning achievement of a long and productive career.

At their core, the partial draft bill released by Senate Democrats and an outline circulated by senior House Democrats were largely identical.

Individuals would be able to purchase insurance through a new federally regulated national exchange, and private companies would be barred from denying coverage or charging higher premiums because of pre-existing conditions. Those who are satisfied with their current coverage could keep it.

Both bills would require individuals to purchase insurance if they could afford it. Waivers would be available in hardship cases. The Senate measure provides for an unspecified penalty for anyone refusing to obey the so-called mandate, and House Democrats are considering a similar approach.

In both the House and Senate, Democrats want to provide subsidies to families with incomes well into the middle class. One option under the Senate plan would phase out subsidies at about $110,000 for a family of four.

House Democrats also are said to be considering a wide-ranging change for Medicaid that would provide a uniform benefit across all 50 states and increase payments to providers. Medicaid is a joint state-federal program of health coverage for the poor.

On a particularly contentious point, the emerging House plan would give people the option of buying a health insurance plan provided by the federal government.

Democrats on the Senate committee embraced a similar provision last week but omitted it from Tuesday's draft in what Sen. Chris Dodd, D-Conn., said was a gesture to Republicans who oppose it.

Senate Democrats say they want to work out a compromise with Republicans, who remain adamantly opposed to a public plan.

Numerous senior Democrats now aging and ailing have worked their entire careers on health care, but no one is more identified with the issue than Kennedy, first elected to the Senate in 1964. In a poignant announcement Tuesday, Dodd said Kennedy, diagnosed a year ago with a brain tumor, will be unable to attend the working sessions of the health committee he chairs beginning next week.