After an 89-8 vote in the Senate, the measure now moves to the Republican-controlled House of Representatives, which is expected to consider it later on Tuesday.
Many Republican House members have already voiced misgivings about the deal's tax hikes on the wealthy and its lack of spending cuts. It is likely to need substantial support from House Democrats in order to pass.
The House was due to reconvene at noon EST on Tuesday to take up the measure. However, House Speaker John Boehner said earlier that decisions had not been made on whether he will allow amendments to the bill or hold a straight up-or-down vote.
Without a deal, some $600 billion worth of automatic tax hikes and spending cuts will be triggered in the first days of 2013, threatening a new US recession.
"We don't think taxes should be going up on anyone but we all knew if we did nothing, they'd be going up on everyone today," said Senate Republican leader Mitch McConnell, who negotiated the eleventh-hour deal with Vice President Joe Biden.
"This shouldn't be the model for how we do things around here, but I think can say that we've done some good for the country," McConnell said in remarks just before the vote.
