Partner Leagues

Partner Leagues are a concept created with the re-organization of the minor leagues into the Professional Development League in 2021. While the bulk of the PDL is comprised of minor league teams affiliated with a major league team, the new system also includes within its orbit five other leagues which receive support from Major League Baseball but are not affiliated with teams.

It is a hybrid category. Four of the leagues are fully professional and operated as independent leagues until 2020: the Atlantic League, the American Association, the Frontier League and the Pioneer League (which was previously part of Organized Baseball as an affiliate league, unlike the other three). The fourth league is an amateur summer collegiate league, the re-formed Appalachian League, which replaces the venerable minor league of the same name that was dissolved as part of the reorganization.