Class High-A was established as a classification level within
Minor League Baseball in 1990 by subdividing the existing
Class A.[1] Class A had been the third-highest level in the minor leagues since 1936 (when it was below
Double-A and Class A1) and a hierarchy of
Triple-A and Double-A above Class A had been in place since 1946.[2]: 15 In 1963, the three classes below Class A (Classes B, C, and D) were abolished, with leagues at those levels moved into Class A.[2]: 15 In 1965, Class A was subdivided for the first time, with the establishment of lower-level
Class A Short Season leagues.
The 1965 hierarchy was in place for 25 years, until Class A was further subdivided in 1990, with Class A-Advanced becoming the third-highest classification:
Three leagues, each previously Class A, received the Class A-Advanced designation: the
California League,
Carolina League, and
Florida State League.[1] This arrangement continued until 2021, when
Major League Baseball (MLB) restructured the minor leagues, eliminating Class A Short Season and discontinuing the use of all historical league names within Minor League Baseball.[3] The existing Class A-Advanced leagues were moved to the Class A level and operated under generic names (
Low-A West,
Low-A East, and
Low-A Southeast) during 2021. The Class A-Advanced level was officially renamed as "Class High-A",[4][5] and also operated three leagues during 2021 with generic names:
High-A Central,
High-A East, and
High-A West.[6] These three High-A leagues had historically been known as the
Midwest League,
South Atlantic League, and
Northwest League—the first two had previously operated at the Class A level, while the latter had previously operated at the Class A Short Season level. Following MLB's acquisition of the rights to the names of the historical minor leagues, MLB announced on March 16, 2022, that the leagues would revert to their prior names, effective with the 2022 season.[7]
In January 2023, it was announced that
Veronica Gajownik had been hired to manage the
Hillsboro Hops, making her the first woman to manage a High-A team.[8]
This section needs expansion with: playoff structure prior to the 2021 re-org. You can help by
adding to it. (June 2021)
On June 30, 2021, Minor League Baseball announced that the top two teams in each league (based on full-season
winning percentage, and regardless of division) would meet in a best-of-five postseason series to determine league champions.[9]