The federal government is reimbursing the Metropolitan Transportation Authority for tunnel repairs made in the wake of Hurricane Sandy.
Senator Chuck Schumer says most of the $886 million will cover repairs to the Montague, Greenpoint and Steinway subway tunnels.
It will also help fortify the system against future storm damage.
Officials say the money represents the first major federal reimbursement to the MTA for Hurricane Sandy-related repairs.
Hurricane Sandy flooded the city's subway system.
In the case of the Montague line that carries the R line across the East River between Manhattan and Brooklyn, repairs are ongoing.