President George W Bush has signed off the two-year bipartisan $167bn (£86bn) US economic stimulus plan.
President Bush said the package was a "booster shot" for the economy
It aims to bolster the world's largest economy and avoid a recession, and will lead to millions of US homes getting tax rebates from May.
The package includes one-off rebates of up to $600 for individuals and $1,200 for couples, plus $300 for each child.
Mr Bush said the plan - passed by Congress last week - was a "booster shot" for the US economy.
As well as the tax rebates, the package will see those on low incomes who do not pay income tax receive a $300 payout.
The aim of the plan is to boost US consumer spending at a time when the continuing housing market slump has raised fears of a wider recession.
"We have come together on a single mission, and that is to put the people's interest first," said President Bush.
While the package was passed by a vote of 81-16 in the Senate and by 380 to 34 in the House of Representatives, some politicians have expressed concerns about what it will do the government's finances.
"This package gets money into the hands of Americans struggling to make ends meet, helps families with children, cuts taxes for small businesses that will create new jobs and stimulates our slowing economy," said House Speaker Nancy Pelosi.