U.S. Transportation Secretary Ray LaHood announced the deal Friday.
Federal officials say the state has five years to pay back the money.
Christie halted the Hudson River tunnel project last year because he feared taxpayers would be saddled with a potential $5 billion in cost overruns. But the state had already received $271 million in federal money to get the project started.
The Christie administration has spent more than $1 million so far to fight the bill the U.S. Department of Transportation handed the state.