List of New York City Subway lines

This article is about the physical trackage used by services. For the service patterns, see List of New York City Subway services.

A schematic map of New York City's subway lines (i.e., Sea Beach, West End, ...) as opposed to services (i.e., N, D, ...).
The Queens Boulevard viaduct of the IRT Flushing Line

The New York City Subway is a heavy-rail public transit system serving four of the five boroughs of New York City. The present New York City Subway system inherited the systems of the Interborough Rapid Transit Company (IRT), Brooklyn–Manhattan Transit Corporation (BMT), and the Independent Subway System (IND). New York City has owned the IND since its inception; the BMT and IRT were taken over by the city in 1940. The former IRT system is now known as the A Division, while the B Division is the combined former BMT and IND systems.

In the New York City Subway nomenclature, a "line" refers to the physical trackage used by trains that are used by numbered or lettered "services"; the services that run on certain lines change periodically. Today, the division or company names are not used publicly, while the line names may occasionally be used.