A package of amendments to the landmark US healthcare reform law, which extends coverage to 32 million more Americans, has passed its final Congress vote.
The US House of Representatives backed amendments by 220 votes to 207. The vote was needed after a number of Republican objections.
The Senate earlier voted for the package by 56-43. Two points, which Democrats say are minor, were deleted.
President Barack Obama has already signed the main bill into law.
He will now be able to apply a final signature, which is expected within days.
The BBC's Richard Lister in Washington says that in recent days Democrats have begun to seize back control of the healthcare argument, and opinion polls suggest that more Americans now believe this reform is a good idea.
However, he says, Republicans are threatening to reform or repeal this legislation should they gain control in the mid-term elections in November.
On Thursday, President Obama responded to that challenge, saying: "I welcome that fight."
He was speaking during a visit to Iowa, as he embarked on a campaign to sell the new programme to the American public.
Senate Republican leader Mitch McConnell said: "Republicans... will continue to fight until this bill is repealed and replaced with commonsense ideas that solve our problems without dismantling the healthcare system we have and without burying the American dream under a mountain of debt."
Mr Obama signed the healthcare bill into law without delay after the previous House vote on Sunday, as he did not need to wait for the Senate and House votes on Thursday.
Those votes were on amendments submitted under a process known as budget reconciliation. The amendments have to relate to budgetary rather than policy issues.
On Wednesday, Senate Republicans submitted 30 amendments - which were all rejected by Democrats during a marathon overnight voting session.
However, Senate parliamentarian Alan Frumin upheld two Republican challenges on points of order under budget reconciliation rules, Senate Democratic aides said.
Jim Manley, spokesman for Senate Majority Leader Harry Reid, said: "After hours of trying to find a way to block this, they (Republicans) found two relatively minor provisions that are violations of Senate procedure which means we're going to have to send it back to the House."
The House vote brought an end to a process the president had labelled "a year of debate and a century of trying".
After Sunday's vote, some supporters of the bill had received threats and abusive messages, prompting them to call police and the FBI.
Democratic House Majority Leader Steny Hoyer said more than 10 Democratic politicians had reported incidents some of which he described as "very serious".
Republicans accused Democrats of playing politics with the threats.
"By ratcheting up the rhetoric, some will only inflame these situations to dangerous levels. Enough is enough. It has to stop," said House Republican Whip Eric Cantor.
Two Republican politicians have said they too were threatened.