Triple-A (officially Class AAA) has been the highest level of play in Minor League Baseball in the United States since 1946. Currently, two leagues operate at the Triple-A level, the International League (IL) and the Pacific Coast League (PCL). There are 30 teams, one per each Major League Baseball (MLB) franchise, with 20 in the IL and 10 in the PCL. Triple-A teams are generally located in smaller cities who do not have major sports league teams such as Syracuse, Toledo, Reno and Omaha as well as larger metropolitan areas without MLB teams that may also have teams in other major sports leagues, such as Austin, Jacksonville, Columbus, Buffalo, and Indianapolis. Four Triple-A teams play in the same metro areas as their parent clubs.
All current Triple-A teams are located in the United States; before 2008, some Triple-A leagues also fielded teams in Canada, and from 1967 to 2020 the Mexican League was classified as Triple-A. Reasons for the relocation of these teams were solely because of costs and attendance. Other than the current two Triple-A leagues, only three other leagues have ever held the classification.
Prior to 1946, the top level of Minor League Baseball was Double-A, which had been established in 1912. The Triple-A classification was created before the 1946 season, and began with all three leagues then in Double-A moving up to the new level:
This structure persisted for the next 75 years with only a few changes:
The IL, PCL, and Mexican League continued as Triple-A leagues until Major League Baseball reorganized the minor leagues prior to the 2021 season. At that time, the IL and PCL were temporarily renamed Triple-A East and Triple-A West, respectively. The Mexican League continues to operate, independently. Following MLB's acquisition of the rights to the names of the historical minor leagues, they announced on March 16, 2022, that the leagues would once again be called the International League and the Pacific Coast League, effective with the 2022 season.
While all current and the majority of past Triple-A teams have been located in the United States, Triple-A teams have also been based in: