The Bergen Street, Grand Army Plaza, and Eastern Parkway–Brooklyn Museum stations opened on October 9, 1920. Service on the IRT Eastern Parkway Line had been extended from Atlantic Avenue to Utica Avenue in August 1920, but the three stations were not ready to open with the rest of the line. This extension was part of an expansion of the subway system known as the Dual Contracts which built not only IRT lines in Brooklyn but also those for the BMT. The BMT Brighton Line was already in use at the time but used trackage that is now part of the Franklin Avenue Shuttle; the opening of the subway line beneath Flatbush Avenue provided a more direct route to Downtown Brooklyn and, eventually, Manhattan. During the 1964–1965 fiscal year, the platforms at Bergen Street, along with those at four other stations on the Eastern Parkway Line, were lengthened to to accommodate a ten-car train of 51-foot IRT cars.
Station layout
The station contains six tracks and two side platforms: the outermost tracks are used by the IRT local trains. To the inside are the IRT express tracks, which slant upward to the inside of the outer local tracks. In between the express tracks are the BMT Brighton Line tracks. Those routes were built at the same time as the tracks at this station as part of the Dual Contracts. A full curtain wall separates the local from the express tracks, though a gap exists in the curtain wall at the end of the station. Both platforms have their original mosaics. The name tablets read "BERGEN ST." in gold Times New Roman font on a blue background and multi-layered green border. The trim line is green with "B" tablets on them on a blue background at regular intervals. At either ends of both platforms, where they were extended in 1964–1965, there are cinderblock tiles with signs reading "BERGEN ST" in sans serif font on a maroon background. The platforms only have columns at the fare control areas and they are i-beam columns painted green.
Exits
Each platform has one same-level fare control areaat the center and there are no crossovers or crossunders. The southbound platform has an unstaffed fare control area containing a bank of three regular turnstiles, two exit-only turnstiles, and two High Entry/Exit Turnstiles. Outside fare control are two staircases going up to the southwestern corner of Flatbush Avenue and Bergen Street and a passage leading to another staircase going up to the northwestern corner. The Manhattan-bound platform has a full-time turnstile bank and token booth. Outside fare control are and two staircases going up to either eastern corners of Bergen Street and Flatbush Avenue, as well as a closed and sealed stair to the southwestern corner of Sixth Avenue and Bergen Street.
