US Senator Max Baucus, a key figure in the drive to reform the American healthcare system, has published his version of a bill.
The Senate Finance Committee, which Mr Baucus chairs, will now consider his draft and suggest amendments.
If the committee approves a bill, it will go before the full Senate.
Passing a healthcare reform bill is President Obama's top priority for 2009, but so far lawmakers have been unable to agree on a bill.
White House spokesman Robert Gibbs said Mr Baucus's bill was an "important building block" that "gets us closer to comprehensive healthcare reform".
Moderate
The House of Representatives is expected to pass a bill which will allow Americans who do not have employer-provided health insurance to choose a publicly-run insurance scheme.
But Mr Baucus's bill will not offer the so-called "public option".
Instead, he would create not-for-profit co-ops, which would compete with private insurers to cover people without employer-sponsored coverage.
Like other draft bills produced by various House committees and the Senate health committee, Mr Baucus's bill would mandate all Americans to get insurance, and would provide subsidies to help less well-off Americans pay for their coverage.
This is a unique moment in history where we can finally reach an objective so many of us have sought for so long
Max Baucus
Chairman, Senate Finance Committee
Q&A: US healthcare reform
But while the House committees proposed to pay for the increased coverage by placing a surtax on families earning over $350,000 a year, Mr Baucus would cover the costs of his proposals by levying new fees on more generous private insurance schemes.
Mr Baucus had hoped to attract Republican support for his plan, which is more moderate than the bills proposed by other committees.
"This is a unique moment in history where we can finally reach an objective so many of us have sought for so long," said Mr Baucus.
"The Finance Committee has carefully worked through the details of health care reform to ensure this package works for patients, for health care providers and for our economy."
Rejected
So far, however, his bill has not received any Republican backers.
And one of the leading Democrats on the committee, Senator Jay Rockefeller, has rejected the plan, because it does not include a public option.
If the Finance Committee does eventually agree on a bill, the full senate will attempt to come up with a bill, based on the versions produced by the Finance Committee and the Health Committee.
Simultaneously, the House of Representatives will attempt to come up with its own draft of a bill.
Once both chambers have approved bills, a conference committee, made up of lawmakers from both houses, will convene to reconcile the two versions.
If both chambers then vote in favour of the reconciled version, it will be sent to President Obama for his approval, and become law.