On April 18–21, 1924, the tunnel was converted to rapid transit and Maverick station opened, with the streetcar loop between the rapid transit platforms. The last streetcar lines to use the underground loop were 114, 115, 116, 117, 118, and 121; these last ran on January 4, 1952, the day before the Revere Extension to the rapid transit line opened. The streetcar loop and portal have since been closed, with parts of the incline now used for pedestrian access. The station has an extra-wide platform as a result of filling in the former streetcar tracks. The abandoned streetcar loop west of the station remains extant.
The MBTA began design work for a renovation of the station in 1998. A $30.8 million construction contract, which also included ventilation work in the East Boston Tunnel, was awarded on May 5, 2005. Construction began with a groundbreaking ceremony on October 4, 2005. The work included an extension of the platforms for six-car trains, replacement of the Maverick Square headhouse, the addition of a new headhouse on Lewis Mall, and the creation of a dedicated busway in Maverick Square. Both headhouses included an elevator to make the station fully accessible. The Lewis Mall headhouse opened on September 22, 2007, allowing the old Maverick Square headhouse to be demolished that November. The renovation was completed in 2009. The final cost was $56.3 million, which included $12.4 million in change orders – of which $8.9 million was due to design errors by the MBTA.