Majorstuen is shared by all the subway lines, and, being located just after the tunnel entrance, it is the only such station not located underground. Majorstuen was originally the end station for Holmenkollbanen, and remained so until the tunnel to Nationaltheatret Station was completed.
After Majorstuen the subway lines split up in three directions. Sognsvannsbanen runs northwards, Holmenkollbanen runs to the northwest while Røabanen and Kolsåsbanen are on a shared track to the west.[1]
The station has three platforms. There are two main platforms facing each other. Behind the platform for outbound trains is a bay platform, used for the trains on the west side of Oslo which terminate at Majorstuen. Such trains are not common, they are usually early-morning trains or trains which are retiring for the evening. Between 2002 and 2004 however, Holmenkollbanen terminated at Majorstuen and all these trains used this platform. Also located on the outbound platform is a Narvesenkiosk, the only such kiosk on the Oslo Metro behind the ticket barriers.