138 Street-Grand Concourse is the first stop in the Bronx, and only stop in the Bronx where 4 and 5 trains normally share the same tracks at a station. The station has three tracks and two side platforms, all 4 trains skip this station during peak direction rush hours, using the middle express track. These Express Trains (indicated as diamond 4’s on the subway map until it became a normal 4 train around 2010) run to Manhattan during the morning rush hours (between about 7:00am and 9:00am), and from Manhattan during the PM rush hour (between about 4:30pm and 6:30pm). This service change is done to slightly reduce delays to 4 trains done by 5 trains when they slowly switch onto the curving tracks to connect down with the 2 train tracks before entering 149 Street-Grand Concourse.
The station has one single exit on a small mezzanine above the middle of the platforms. Each platform contains two staircases near each other that lead up to this mezzanine. The staircases from the Downtown platform meet at an intermediate landing before a shorter set of steps leads up to the mezzanine. On the mezzanine, a single bank of turnstiles faces the token booth. Station exits are provided by a total of 3 streetstairs lead up to the T-intersection of 138 Street and the southern end of the Grand Concourse. There are 2 streetstairs to the NE corner directly next to a bridge used by a long access ramp to and from the Major Deegan Expressway (I-87) from the Grand Concourse. The other streetstair is nestled between the Grand Concourse and an overpass used by Metro-North.
For platform decorations, each platform has a dual-contracts era blue and brown mosaic trimline, with MH lettering. This MH is for the station’s former name, Mott Haven. Former Mott Avenue name tablets and mosaic signs on the large, tiled platform columns located on the Downtown platform have been covered up by regular black subway signs that say 138 on the columns and 138 Street on the name tablets (the brown border of the name tablets is still visible). There are platform columns only for the wider middles of each platform (about half the platform lengths), at the ends of each platform, as they get narrower the columns end. These are tiled on the Downtown platform, but normal metal beams, painted a teal color on the Uptown platform.
At the very ends of each platform, there is a tiny portion of each platform that was extended and have 1950s cinderblock-style wall tiling with a single blue line with 138th St written a few times along it.
Photo 1: November 4, 2003; 2 & 3: Summer 2004; 4-7: January 29, 2005; 8-21: January 7, 2021; 22: October 10, 2012