Timeline of Major League Soccer

The following is a timeline of organizational changes in Major League Soccer (MLS), a professional soccer league in the United States and Canada that began play in 1996 with 10 teams and by 2024 now has 29 teams. A 30th team, San Diego FC, will play by 2025. This article includes expansions, contractions, renamings of clubs and conference realignment.

1996 (10 teams)
The league operated its first inaugural season in 1996 with 10 teams and two conferences.

1997 (10 teams)
Kansas City Wiz would be renamed to the Kansas City Wizards in the following season.

1998–1999 (12 teams
The league expanded for the first time in 1998 with Miami Fusion and Chicago Fire. New York/New Jersey MetroStars would be renamed to MetroStars by the same season.

2000–2001 (12 teams)
In 2000, the league realigned to three divisions, with a new division: the Central Division. The Eastern and Western Conferences were renamed to the Eastern and Western Divisions respectively. San Jose Clash would also rebrand to the San Jose Earthquakes.

2002–2004 (10 teams)
Prior to the 2002 MLS season, Miami Fusion of the Eastern Division and Tampa Bay Mutiny of the Central Division folded. The league returned to the two-conference format for the season with a similar alignment to the 1997 season, only with Chicago Fire moving to the Eastern Conference.

2005 (12 teams)
Chivas USA and Real Salt Lake were both added to the Western Conference for the 2005 expansion; The Kansas City Wizards were subsequently moved to the Eastern Conference to even the conferences out.

2006 (12 teams)
The San Jose Earthquakes would relocate to Houston to become the Houston Dynamo.

2007 (13 teams)
Toronto FC was added to the Eastern Conference during 2007 expansion, adding a team in Canada for the first time.

2008 (14 teams)
The San Jose Earthquakes returned to the Western Conference for the 2008 season after a 2-year hiatus.

2009 (15 teams)
Seattle Sounders FC was added to the Western Conference for the 2009 season, succeeding USL First Division team of the same name.

2010 (16 teams)
Philadelphia Union was added to the Eastern Conference for the 2010 season.

2011 (18 teams)
The Portland Timbers and Vancouver Whitecaps FC were both added to the Western Conference with both teams being successors of USL teams. Houston Dynamo subsequently switched to the Eastern Conference to make both conferences even. Kansas City Wizards rebranded to Sporting Kansas City prior to this season.

2012–2014
Montreal Impact was added to the Eastern Conference for the 2012 season, succeeding a USL First Division team of the same name.

2015–2016 (20 teams)
New York City FC and Orlando City SC were both added to the Eastern Conference, the latter of which was a successor of a USL Pro team of the same name; subsequently Sporting Kansas City was relocated back to the Western Conference after 9 seasons to make both conferences even. Chivas USA would fold prior to the 2015 season.

2017 (22 teams)
Atlanta United FC and Minnesota United FC were added to the Eastern and Western Conferences respectively; the latter of which was the successor to the NASL team of the same name.

2018 (23 teams)
Los Angeles FC was added to the Western Conference for the 2018 season.

2019 (24 teams)
FC Cincinnati was added to the Eastern Conference after spending 3 years in the USL.

2020 (26 teams)
Inter Miami CF and Nashville SC were both added to the Eastern and Western Conferences for the 2020 season; due to scheduling difficulties due to Nashville SC not participating in the MLS is Back Tournament, the club moved to the Eastern Conference after the event. Chicago Fire SC rebranded to Chicago Fire FC.

2021 (27 teams)
Austin FC was added to the Western Conference for the 2021 season. Montreal Impact rebranded to Club de Foot Montréal.

2022 (28 teams)
Charlotte FC was added to the Eastern Conference for the 2022 season; Nashville SC subsequently relocated to the Western Conference to even the conferences.

2023–2024 (29 teams)
St. Louis City SC was added to the Western Conference for the 2023 season; Nashville SC relocated to the Eastern Conference for a second time.

2025 (30 teams)
San Diego FC will be added to the Western Conference for the 2025 season.