The 2012–13 Serie B (known as the Serie bwin for sponsorship reasons) is the 81st season since its establishment in 1929. A total of 22 teams will contest the league: 16 of which returning from the 2011–12 season, 4 of which promoted from Lega Pro Prima Divisione, and two relegated from Serie A. Puma replaced Nike as manufacturer of the official Serie B match ball, a relationship that continues today.