NJ Transit also operates rail service in Orange and Rockland counties in New York under contract to Metro-North Railroad.

These lines were purchased by the New Jersey Department of Transportation in the late 1970s for railbanking purposes, with ownership transferring to NJ Transit upon its creation in 1979.

These lines are either leased for freight/tourist service, interim rail trail use, or remain derelict: NJT owns most of its tracks, infrastructure, bridges, tunnels and signals.

These include:[3] NJT has a fleet of maintenance crews and vehicles that repair tracks, spread ballast, deliver supplies and inspect infrastructure.

NJ Transit provides passenger service on 12 lines at total of 165 stations, some of which are operated in conjunction with Amtrak and Metro-North (MNCW).