Reid's Senate measure would require most Americans to carry health insurance and would provide subsidies for those at lower incomes. It also would mandate that large companies provide coverage to their workers.
The bill also includes a government-run insurance option that lets states choose whether to participate.
The full text of the 2,074 page bill was posted on the Internet Wednesday night.
The bill would cost $849 billion and cover 31 million more Americans, news agencies and other media outlets reported earlier Wednesday.
Democratic leadership aides told wire services and other sources that the Congressional Budget Office had estimated that under the bill, 94 percent of American citizens would have health insurance. New taxes and new cuts to Medicare spending would make up for the cost of the bill, and the legislation would cut the projected Federal budget deficit by $127 billion by 2019, the sources said.
The bill, which Reid is aiming to bring to the Senate floor to begin debate as early as Friday, is ostensibly a combination of the legislation passed earlier this fall by the Senate Health Committee and the Senate Finance Committee. But in reality Reid spent weeks tinkering with it in an attempt to round up the 60 votes he needs to pass the legislation.
Republicans pledged a tough debate over the measure in the days ahead.
"This bill has been behind closed doors for weeks," said Sen. Mitch McConnell of Kentucky, the Republican leader. "Now, it's America's turn, and this will not be a short debate. Higher premiums, tax increases and Medicare cuts to pay for more government. The American people know that is not reform."
The Democrats' late-afternoon caucus came after a day of last-minute lobbying by Reid, along with Vice President Joe Biden and other influential players, to drum up support for the bill.
Reid needs the support of all 58 Democrats and two Independents in the Senate in order to begin debate on the bill and forestall a promised Republican filibuster.
This afternoon, three conservative Democrats holed up in Reid's office for a briefing. Sen. Blanche Lincoln of Arkansas, Sen. Mary Landrieu of Louisiana, and Sen. Ben Nelson of Nebraska had all indicated that they would not commit to support the bill until they had seen the text.
---- Compiled from wire reports and other media sources