Lawmakers held two votes into the late hours of Sunday – the first on procedural issues, and the second to pass a Senate version of a health reform bill.
Mr Obama is expected to sign the legislation into law shortly.
This is a historic moment as liberals have been pressing to extend healthcare for Americans for nearly 100 years, and it looks as if President Obama has achieved it, the BBC’s Mark Mardell reports from Washington.
Our correspondent says it is a much-needed victory for Mr Obama, but that it could damage his party in the polls if Republicans manage to galvanise opponents to the measure.
In a last-minute move designed to win the support of a bloc of anti-abortion lawmakers, Mr Obama earlier on Sunday announced plans to issue an executive order assuring that healthcare reform will not change the restrictions barring federal money for abortion.
The House must now vote on a package of reconciliation “fixes” sought by some Democrats to the legislation.
If the House approves the package of changes to the Senate bill, the Senate would take it up next week using a procedure known as reconciliation.
That would allow budget provisions to be approved with 51 votes – rather than the 60 needed to overcome blocking tactics.
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