*Event date: 2026-09-02*

Major League Soccer will send all 27 of its United States-based clubs into the 2027 U.S. Open Cup, restoring full league participation for the first time since the 2023 edition. The move marks a major shift in how the league participates in U.S. knockout competition, after recent seasons in which only a limited number of MLS sides were entered.

The announcement matters because the Open Cup has long been one of the few domestic tournaments that puts professional clubs from different levels of the U.S. game into the same bracket. ESPN reported that MLS has now lifted the rule that had capped clubs at two non-league competitions, opening the way for teams to appear in the U.S. Open Cup, Leagues Cup and Concacaf Champions Cup in the same year alongside the regular season. That change gives the league more flexibility, but it also brings MLS back into a tournament it had entered only in reduced numbers in recent years.

For the 2026 Open Cup, just 16 U.S.-based MLS clubs took part. ESPN also noted that 18 MLS clubs, including Canadian teams, were involved in the Leagues Cup this year. The contrast with 2027 is stark: instead of selective entry, every U.S.-based MLS side will be back in the Open Cup draw.

MLS clubs will join the competition in the round of 64, which is scheduled to begin in July of next year. The timing is meant to align with the start of the league’s new summer-to-spring competition calendar for the 2027-28 regular season. That schedule change gives the Open Cup a new place in the MLS year, rather than forcing clubs to fit the tournament into an older calendar structure that did not match the league’s future format.

The league will also get a small competitive benefit at the start of the tournament. MLS clubs will have hosting priority for their opening match, a detail that could matter in a competition where lower-division and amateur sides often view home draws as a significant advantage. After the round of 64, a live draw will determine the round-of-32 and round-of-16 matchups and hosting rights.

The tournament calendar for 2027 is already mapped out further than the first rounds. ESPN reported that the round of 32 is set for Sept. 14 and Sept. 15, while the round-of-16 dates will be confirmed later. The quarterfinals are scheduled for Nov. 23-24, followed by the semifinals on Dec. 1 and the final on Dec. 15. That stretched schedule means the competition will now run deep into the end of the year rather than finishing in a more compressed summer window.

Roster rules are changing as well. The upcoming edition will expand gameday squads from 18 players to 20. MLS said the enlarged squad size will allow clubs to draw from contracted first-team players, MLS NEXT Pro players and academy players, which it said should give younger players competitive minutes while helping teams manage multiple competitions. The adjustment suggests MLS wants the Open Cup return to work as both a sporting opportunity and a squad-management exercise.

Nelson Rodriguez, MLS executive vice president of sporting and matchday, said the Lamar Hunt U.S. Open Cup connects leagues, clubs and fans in a unique way and gives MLS teams a chance to write a special chapter in the tournament’s history while pursuing Concacaf Champions Cup qualification. That framing reflects the practical and symbolic value of the competition: it is a pathway to continental football, but also a reminder of the league’s place inside the wider U.S. game.

The 2026 tournament is still not over. Four MLS teams remain in the semifinals, which are scheduled for Sept. 16, with Columbus Crew hosting Orlando City SC and the Colorado Rapids hosting St. Louis City. The eventual winner of the Columbus-Orlando semifinal will host the final on Oct. 21. Even as that edition runs its course, the larger significance of the 2027 announcement is already clear. MLS is moving from limited involvement back to full participation, and the Open Cup is set to regain a more complete field of the league’s U.S. clubs.