WASHINGTON — Senate Democrats passed a landmark health care bill in a climactic Christmas Eve vote that could usher in near-universal medical coverage for the first time in the country’s history.

The 60-39 vote on strict party lines now launches a high-stakes effort to reconcile the disparities between House and Senate versions of the bill.

It was an unusual early morning session Thursday as senators gathered at 7 o’clock to cast their fateful votes.

It was the 25th day of debate, second-longest in Senate history, and Vice President Biden made a rare appearance to oversee the roll call.

At the White House, President Obama called the vote historic and said that because of it, “we are incredibly close to making health insurance reform a reality in this country. Our challenge now is to finish the job.”

The hardened differences between the House and Senate versions—on abortion, taxes and the government’s role in the insurance market—may weaken under political pressure to act quickly on Obama’s goal of overhauling a system that provides world-class care for millions of Americans but is marked by huge gaps in insurance coverage, uneven quality and skyrocketing costs.

Still looming are volatile debates among Democrats over abortion and a range of proposed health-benefit taxes opposed by organized labor and others.

But other major obstacles are beginning to diminish. One of the most divisive issues among Democrats—the idea of creating a government-run insurance program known as the public option — is now effectively off the table.

And for all the differences between the two bills, they have vast expanses of common ground.

The final bill almost certainly will increase by at least 30 million the number of people covered by government and private health insurance. It will for the first time require most individuals to buy health insurance. But it also will offer federal subsidies to help pay premiums, impose penalties on employers that do not offer workers affordable policies and set up an insurance exchange in which individuals can shop for coverage if they have no job-based option.

Insurance companies will have to end practices — setting caps on total payments, for example, or denying coverage on the basis of a pre-existing condition — that have made it hard for people to get coverage when they get sick or have a chronic disease.

Young adults will be able to stay longer on their parents’ health plan. Families will pay nothing for preventive health care such as well-baby visits and mammograms.

And health care professionals will be given incentives to provide more cost-effective care — and face penalties if they do not.

An exhausted Senate Majority Leader Harry Reid, D-Nev., initially cast a “no” vote by mistake, then quickly corrected himself as fellow senators burst out laughing. Reid lightheartedly credited this to his “bipartisanship.”

The majority leader went on to say, “This is a victory because we’ve affirmed that the ability to live a healthy life in this great country is a right, not a privilege.”

But all that comes at a cost. The Senate bill would spend $871 billion over 10 years, although it would raise taxes and cut spending in other areas by even more and so reduce the federal deficit over time.

Despite bipartisan consensus that the status quo is unacceptable, the Senate’s debate on health care began and ended in an especially bitter and personal atmosphere of partisanship.

No Republicans voted for the bill, and GOP leaders did everything they could to delay the vote until Christmas Eve. They spent more than 80 hours in Senate floor speeches denouncing the Democrats’ bill as an ill-considered and pork-laden monstrosity that would do little to curb health care costs and insurance premiums.

“This fight isn’t over,” said Senate Minority Leader Mitch McConnell, R-Ky. “I guarantee you the people who voted for this bill are going to get an earful when they finally get home for the first time since Thanksgiving.”

The only Republican who did not vote against the bill was Sen. Jim Bunning of Kentucky, who was absent because of family commitments, his office said.

The House and the Senate will not reconvene until mid- January. Democrats hope to send a final bill to the White House in late January or early February.

For the third time since Sunday night, Sen. Robert C. Byrd of West Virginia, 92, was wheeled into the Senate so he could cast a vote Democrats could not do without.

For Democrats, there was an air of bittersweet celebration, underscored by the presence of Victoria Reggie Kennedy in the visitors gallery that overlooks the Senate floor. Her husband, Sen. Edward M. Kennedy of Massachusetts, died in August after a 47-year Senate career spent working relentlessly for universal health care.

“With Sen. Ted Kennedy’s booming voice in our ears, with his passion in our hearts, we say, as he said: The work goes on, the cause endures,” said Reid, echoing words Kennedy uttered in his most famous speech, delivered at the 1980 Democratic National Convention when he conceded the presidential nomination to President Jimmy Carter.

New York Gov. David A. Paterson called the bill “a historical accomplishment” but said that “it adds close to an additional $1 billion annually in new state Medicaid costs to New York.”

“This could result in a 15 per-cent reduction in payments to providers, meaning hospitals, nursing homes, home health agencies and community clinics could ultimately face these reductions because of strained state and city budgets,” Paterson said, adding that he hopes that those issues will be addressed and corrected during the conference committee negotiations.

New York Sens. Charles E. Schumer and Kirsten E. Gillibrand, both Democrats, hailed the bill.

“The bill is good for Americans and good for New Yorkers,” Schumer said. “It cuts the waste, fraud, abuse and duplication we all know permeates our health care system that drives costs up for families and, at the same time, covers millions of middle-class people who are not covered right now.”

He said the bill “specifically shields 800,000 New York seniors from Medicare cuts.”

Gillibrand said, “There are 2.7 million New Yorkers who are now one step closer to getting affordable, quality health care coverage, which will also reduce the hidden tax to New York for caring for the uninsured.”

Republicans were withering in their criticism. House Minority Leader John A. Boehner, ROhio, said, “Not even Ebenezer Scrooge himself could devise a scheme as cruel and greedy as Democrats’ government takeover of health care.

“Sen. Reid’s health care bill increases premiums for families and small businesses, raises taxes during a recession, cuts seniors’ Medicare benefits, adds to our skyrocketing debt and puts bureaucrats in charge of decisions that should be made by patients and doctors.”

The Associated Press contributed to this report.