The price tag would be $849 billion over 10 years, covered by a number of new taxes and cuts in Medicare costs, Reid said during a presentation on Capitol Hill.
That would reduce predicted budget deficits by $127 billion by 2019, the largest saving of any of the plans currently being offered by congressional Democrats, The Washington Post reported.
Reid plans to file the legislation formally Friday evening. A procedural vote to place the measure on the Senate floor probably would occur Saturday, his office said.
The plan would provide coverage to 94 percent of Americans by dramatically expanding Medicaid and create options for people without access to affordable coverage, Reid said.
One of those options, Reid said, would be a government-run "public" option that liberals have demanded, although states could "opt out" of the public plan.
Republicans plan to fight the legislation, which they call a government takeover of healthcare that will increase taxes and healthcare costs for individuals, The New York Times reported.
"It's going to be a Holy War," Sen. Orrin Hatch, R-Utah, said.
President Barack Obama called the development "another critical milestone in the health reform effort."
"I was particularly pleased to see that the Congressional Budget Office has estimated that the bill will reduce the deficit by $127 billion over the next ten years and as much as $650 billion in the decade following, saving hundreds of billions while extending coverage to 31 million more Americans," the president said in a statement released by the White House.
"Just yesterday, a bipartisan group of more than 20 leading health economists released a letter urging passage of meaningful reform and praising four key provisions that are in the Senate legislation: a fee on insurance companies offering high-premium plans, the establishment of an independent Medicare commission, reforms to the health care delivery system, and overall deficit neutrality," Obama said. "The economists said that these provisions 'will reduce long-term deficits, improve the quality of care, and put the nation on a firm fiscal footing.' Those are precisely the goals we should be seeking to attain."