The Senate has passed legislation to block the impact of across-the-board tax increases and spending cuts that make up the fiscal cliff.
The vote was an overwhelming 89-8 and came well after midnight on New Year's Day.
A House vote is expected before Wednesday.
The White House-backed legislation would prevent middle-class taxes from rising, and raise rates on incomes over $400,000 for individuals and $450,000 for couples.
It also blocks spending cuts for two months, extends unemployment benefits for the long-term jobless, prevents a 27 percent cut in fees for doctors who treat Medicare patients and prevents a spike in milk prices.
A last-minute addition would also prevent a $900 pay raise for members of Congress from taking effect in March.