Everything you need to know about MLB's postseason roster rules

MLB.com has outlined the postseason roster rules ahead of the 2026 playoffs, which begin on September 29. Each team carries a 26-player roster per series, with eligibility requiring players to have been on a club's 40-man roster or 60-day injured list prior to September 1. Exceptions exist allowing players outside those criteria to petition the commissioner's office for postseason eligibility, provided they were in the organization on August 31 and are replacing an injured player.