Milano is served by four subway lines. The Blue Line M4 - Linate - S. Cristoforo - is under construction
- Red Line M1: Sesto F.S. - Rho Fiera Milano / Bisceglie
- Green Line M2: Gessate / Cologno Nord - Assago Milanofiori Forum / P.za Abbiategrasso Chiesa Rossa
- Yellow Line M3: Comasina - San Donato
- Lilac Line M5: Bignami Parco Nord - San Siro Stadio
The system is supplemented by the Passante underground rail link which connects urban and suburban railway stations to the subway network.