The B15 bus route runs between the Woodhull Medical and Mental Health Center and Flushing Avenue (J and ​M) subway station in Bedford–Stuyvesant, and John F. Kennedy International Airport's Terminal 5 in Queens.

Alternate buses during rush hours and weekends short turn at Drew Street/Elderts Lane on Linden Boulevard in Spring Creek, at the border with Lindenwood, Queens.

[1][4][5] The B15 bus route heads south through Bedford–Stuyvesant along Marcus Garvey Boulevard (southbound) and Lewis Avenue (northbound).

B15 buses then terminate at the AirTrain JFK's Lefferts Boulevard station, within the grounds of John F. Kennedy International Airport.

[7][8][9] The Yates Avenue and Flatbush Railroad was organized in 1881 to build a branch of the Broadway Railroad, beginning at Broadway and Yates Avenue (present-day Marcus Garvey Boulevard) in Bedford–Stuyvesant, continuing south on Yates to Fulton Street, then east on Fulton, where it ran over the Brooklyn City Rail Road's Fulton Street Line to Troy Avenue, and continued south on Troy to end at Bergen Street.

[20] By this time, the B10 had been extended east along Linden Boulevard to Drew Street/Elderts Lane in New Lots/Spring Creek, near the Brooklyn-Queens border.

[18][20] This extension had been proposed around 1960 to serve the Cypress Hills and Louis Heaton Pink public housing complexes in New Lots.

[25][26] On October 12, 2009, buses on the B15 were equipped with luggage racks, as part of a ten-bus pilot program on airport bus services to improve passenger flow.

[26][30] On September 8, 2013, B15 buses stopped directly serving the Brooklyn General Mail Facility loop due to low ridership.