With a daily average of 9,848 tapped entries, Union Station is the third-busiest in the system, behind Metro Center and Foggy Bottom–GWU.

The station features an island platform with two exits, one mid-platform mezzanine leading to the main hall of Union Station and Massachusetts Avenue and the one northern exit leading to 1st Street NE and to the main boarding concourse.

It was renamed to simply "Union Station" in 1982 following the closure of the National Visitor Center.

[6] The street-level entrance on First Street, built into the existing retaining wall, was rebuilt to accessible-compliant standards, adding more space for extra fare gates and connections between the platform and track level.

However, prior to the station's opening, the tunnel was boarded up and the space is now used by WMATA to store equipment.