NJ Transit owes the federal government $271 million for the Hudson River rail tunnel that Gov. Chris Christie scrapped last month.
The Federal Transit Administration on Monday sent the railroad the bill, saying interest and penalty charges will be added.
The Record newspaper reported the FTA also said it would launch a "complete audit" of the Access to the Region's Core project to determine how much federal funds still have not been spent.
The $8.7 billion project to construct a rail tunnel between New Jersey and New York was 15 years in the making when Christie pulled the plug, citing cost overruns.
Officials aren't saying where NJ Transit will get the money to pay the bill.
Information from: The Record, http://www.northjersey.com