State is unique among Orange Line stations as it was built on two levels to fit under the narrow section of Washington Street while crossing the East Boston Tunnel.
The southbound side platform is above the northbound track and furthermore staggered considerably south of the northbound side platform.
The southbound platform is connected to the rest of the station by a lengthy pedestrian passageway, originally known as "the speedway".
The Blue Line has two side platforms under State Street and the Old State House.

The station's headhouses are located between Government Center and the Financial District.
State station has six entrances spread out over nearly 1,000 feet (300 m); after consolidation and reconstruction by the MBTA, all entrances serve both lines in all directions.
One entrance is built into the basement of the Old State House and four into commercial buildings.
The northernmost entrance, which is accessed from an unmarked stairwell under 28 State Street on Government Center Plaza, was originally constructed to serve Adams Square but now primarily serves Boston City Hall.

Three entrances are fully accessible with elevators to platform level: Old South Meeting House (Washington Street at Milk Street), 53 State Street, and 60 State Street.
The other three entrances - Old State House (State Street at Devonshire Street), Devonshire Street at Water Street, and Government Center Plaza - are not accessible.
An additional elevator connects the northbound Orange Line platform with the eastbound Blue Line platform and southbound Orange Line platform, while an accessible ramp connects the westbound Blue Line and northbound Orange Line platforms.
In May 2020, the MBTA awarded a design contract for accessibility renovations at State and Chinatown.
The work at State includes a new elevator at the City Hall entrance, replacements of two existing elevators, and renovation of the Milk Street entrance.
State is unique among Orange Line stations as it was built on two levels to fit under the narrow section of Washington Street while crossing the East Boston Tunnel. The southbound side platform is above the northbound track and furthermore staggered considerably south of the northbound side platform. The southbound platform is connected to the rest of the station by a lengthy pedestrian passageway, originally known as "the speedway". The Blue Line has two side platforms under State Street and the Old State House.
The station's headhouses are located between Government Center and the Financial District. State station has six entrances spread out over nearly 1,000 feet (300 m); after consolidation and reconstruction by the MBTA, all entrances serve both lines in all directions. One entrance is built into the basement of the Old State House and four into commercial buildings. The northernmost entrance, which is accessed from an unmarked stairwell under 28 State Street on Government Center Plaza, was originally constructed to serve Adams Square but now primarily serves Boston City Hall.
Three entrances are fully accessible with elevators to platform level: Old South Meeting House (Washington Street at Milk Street), 53 State Street, and 60 State Street. The other three entrances - Old State House (State Street at Devonshire Street), Devonshire Street at Water Street, and Government Center Plaza - are not accessible. An additional elevator connects the northbound Orange Line platform with the eastbound Blue Line platform and southbound Orange Line platform, while an accessible ramp connects the westbound Blue Line and northbound Orange Line platforms. In May 2020, the MBTA awarded a design contract for accessibility renovations at State and Chinatown. The work at State includes a new elevator at the City Hall entrance, replacements of two existing elevators, and renovation of the Milk Street entrance.
State station