The MBTA renovated most Red Line stations for accessibility in the 1980s and 1990s. Planning began for modifications to Charles/MGH in the late 1990s. Although the station was determined to be eligible for inclusion on the National Register, it was in poor condition: the cast stone cladding was spalled and cracked, water infiltration had rusted steel and damaged plaster, and the mezzanine level was overcrowded. The platforms were pitted, columns were rusted, and paint was peeling. Three options were developed in a 2000 design report: rehabilitation of the existing station with added elevators, a new surface=level station entrance slightly to the east inside the traffic circle, and a surface-level entrance at Cedar Street with a footbridge above the tracks and ramps down to the platforms. The second option was recommended.