On September 29, 1963, several Brooklyn streets including Sumner Avenue were turned into one-way streets; Sumner Avenue would become southbound only. Northbound B10 buses were rerouted onto Lewis Avenue at this time. 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. This extension had been proposed around 1960 to serve the Cypress Hills and Louis Heaton Pink public housing complexes in New Lots. The bus would serve Brooklyn General Mail Facility in Spring Creek when it opened in 1991. In 1993, the route was extended to its current terminal at John F. Kennedy International Airport's Terminal 4 in Jamaica, Queens. When the route was extended to Kennedy Airport it was redesignated as the B15 (the previous designation for a route between City Hall and Downtown Brooklyn) to avoid confusion with the , an existing route serving the airport, at the time operated by Green Bus Lines (now part of MTA Bus Company).