It was inaugurated on April 9, 2005, with the first official reserve game being a 2–0 victory by Chivas USA over the host San Jose Earthquakes.
[1] Each club played ten games consisting of home-and-away matches versus each of its five divisional opponents.
In 2013, the schedule of the MLS Reserve League was integrated with the schedule of the USL Pro, with teams from each league playing each other.
Matches between teams of each league would be scheduled resulting in more games for all clubs.
Starting in 2015, MLS clubs must either affiliate with a USL Pro club or create their own team in the USL Pro.