6 (New York City Subway service)

The 6 Lexington Avenue Local and <6> Pelham Bay Park Express are two rapid transit services in the A Division of the New York City Subway. Their route emblems, or "bullets", are colored forest green since they use the IRT Lexington Avenue Line in Manhattan. Local service is denoted by a (6) in a circular bullet, and express service is denoted by a <6> in a diamond-shaped bullet. On the R62A rolling stock, this is often indicated by LEDs around the service logo to indicate local or express service to riders. The LEDs illuminate in a green circle pattern for 6 local trains and in a red diamond pattern for <6> trains.

The 6 operates 24 hours daily between Pelham Bay Park in the Bronx and Brooklyn Bridge–City Hall in Lower Manhattan, making all stops in Manhattan. Additional service short turns at Parkchester in the Bronx during weekday rush hours and middays and does not operate to or from Pelham Bay Park; during this time, 6 trains that originate and terminate at Parkchester make all stops in the Bronx, while trains that serve the full route make express stops in the Bronx between Parkchester and Third Avenue–138th Street in the peak direction and are labeled as <6> Express trains; when the <6> Express is not running, 6 trains originate and terminate at Pelham Bay Park and make all stops in the Bronx.

The 6 in its current format has run since the implementation of the IRT "H" system in 1918. Since 1920, it has remained largely unchanged, running between Pelham Bay Park and City Hall with a peak-express variant in the Bronx. In 1945, the city closed the City Hall Loop station, the 6's former southern terminal in Manhattan. Since then, most 6 trains have terminated at Brooklyn Bridge, with a few exceptions in later years. In 2023, the 6 was the busiest route in the subway system, carrying around 140 million passengers.