Overview
120 affiliated clubs across four classifications, developing every player who reaches the majors.
Minor League Baseball is the affiliated development system beneath the majors. Since a 2021 restructuring, 120 clubs are distributed evenly across four classifications — Triple-A, Double-A, High-A and Single-A — with each of the 30 major-league organisations operating exactly one club at each level.
Below the affiliated system sit the complex leagues, the Arizona Fall League and a wide range of independent leagues, which operate outside MLB's control and often serve as a route back for released players.
Season Format
History
Organised minor-league baseball dates to the National Association of 1901, which for a century negotiated with the majors as an independent body. The farm system as it is now understood was built by Branch Rickey with the Cardinals in the 1920s and copied league-wide.
In 2021 MLB took direct control, cutting the affiliated ranks from 160 clubs to 120 and imposing facility standards, higher minimum salaries and provided housing. The reduction was contentious in the forty-plus communities that lost their clubs; the working conditions it addressed had been the subject of long-running litigation.
Minor-league baseball remains a mass-attendance business in its own right, drawing tens of millions of spectators a year at ticket prices far below the majors.
Governance
Minor League Baseball has been operated directly by Major League Baseball since 2021. Players have been represented by the MLB Players Association since 2022.