J/Z (New York City Subway service)

The J Nassau Street Local and Z Nassau Street Express are two rapid transit services in the B Division of the New York City Subway. Their route emblems, or "bullets", are colored brown. The services use the BMT Nassau Street Line in Lower Manhattan.

The J operates 24 hours daily, while the Z is a variant to the J and operates only in the peak direction during rush hours; both services operate between Jamaica Center–Parsons/Archer in Jamaica, Queens, and Broad Street in Lower Manhattan. When the Z operates, the two services form a skip-stop pair between Sutphin Boulevard–JFK and Myrtle Avenue/Broadway and also make express stops between Myrtle and Marcy Avenues in Brooklyn. Midday J service also makes express stops between Myrtle and Marcy Avenues and all stops along the full route other times.

The J/Z's current skip-stop pattern was implemented in 1988. The J/Z is derived from four routes:

• The JJ/15 between Broad or Chambers Streets in Lower Manhattan and 168th Street in Queens
• The KK between 57th Street/Sixth Avenue in Midtown Manhattan and 168th Street in Queens
• The QJ between Brighton Beach (Coney Island August 1968–January 1973) in Brooklyn and 168th Street in Queens
• The 14 between Broad or Chambers Streets in Lower Manhattan and Canarsie–Rockaway Parkway in Brooklyn