Washington ? Health care legislation heading for the Senate floor will give millions of Americans the option of purchasing government-run insurance coverage, Majority Leader Harry Reid announced Monday, although he stopped short of claiming the 60 votes needed to pass a plan steeped in controversy.

Reid, D-Nev., said individual states would have the choice of opting out of the program.

His announcement was cheered by liberal lawmakers, greeted less effusively by the White House and noted with a noncommittal response by Democratic moderates whose votes will be pivotal.

Sen. Olympia Snowe of Maine, the only Republican to vote with Democrats on health care so far this year, issued a statement saying she was “deeply disappointed” in the approach the Democratic leader had chosen.

Reid said, “While the public option is not a silver bullet, I believe it’s an important way to ensure competition and to level the playing field for patients with the insurance industry.” He said a long-delayed Senate debate on President Barack Obama’s call for an overhaul of the health care system would begin as soon as the Congressional Budget Office completes a mandatory assessment of the bill’s cost and impact on coverage.

Changes on the public option — and numerous other provisions in the measure — are possible during a debate expected to last for weeks.

And officials said Reid had prepared several variations of key provisions so he could make adjustments in his bill at the last minute and still make sure he was within Obama’s target of a $900 billion price tag over a decade.

Both the House and Senate are struggling to complete work by year’s end on legislation extending coverage to millions who lack it, to ban insurance industry practices such as denying coverage because of pre-existing medical conditions and to slow the rise in medical costs nationally.

As in the Senate, attempts to complete drafting a measure in the House have been delayed by internal Democratic divisions on the details of a government-run option. Differences in bills passed by the House and Senate would have to be reconciled before any legislation reached Obama’s desk.

In an appearance at a Florida senior center during the day, Speaker Nancy Pelosi suggested a new name for the same approach to ease the opposition. She suggested “the consumer option.” Rep. Debbie Wasserman Schultz, D-Fla., appearing at Pelosi’s side, used the term “competitive option.”

Critics say that by any name, the approach amounts to a government takeover of the insurance industry.

In deference to moderates, Reid also said he was including a provision for nonprofit co-ops to sell insurance in competition with private companies.

Senate Democratic officials say the bill Reid envisions would require most individuals to purchase insurance, with exemptions for those unable to find affordable coverage. Large businesses would not be required to provide insurance to their workers, but would face penalties of as much as $750 per employee if any qualified for federal subsidies to afford coverage on their own.