^Fort Wayne played in the International Hockey League from 1990 to 1999 (for the current franchise, there had been another Komets franchise that played in the IHL from 1952 to 1990), the UHL/IHL from 1999 to 2010, and the CHL from 2010 to 2012. They joined the ECHL as of the 2012–13 season.
^Kalamazoo previously played in the UHL/IHL from 2000 to 2009. They joined the ECHL as of the 2009–10 season.
^The Toledo franchise had an original run from 1991 until 2007, but voluntarily suspended their membership after the 2006–07 ECHL season in order to demolish the Toledo Sports Arena in order to build the Lucas County Arena. The new owners of the team also changed its nickname from Storm to Walleye.
^Allen played in the CHL from 2009 to 2014 before joining the ECHL for the 2014–15 season
^Missouri played in the CHL from 2009 to 2014 before joining the ECHL for the 2014–15 season.
^Rapid City played in the CHL from 2008 to 2014 before joining the ECHL for the 2014–15 season.
^Tulsa played in the CHL from 1992 to 2014 before joining the ECHL for the 2014–15 season.
^Wichita played in the CHL from 1992 to 2014 before joining the ECHL for the 2014–15 season.
^Brampton played in the CHL before joining the ECHL for the 2014–15 season.
^Colorado played in the CHL from 2003 to 2011 before joining the ECHL for the 2011–12 season.
^Columbia voluntarily suspended their membership for the 2008–09 season as it tried to build a new arena. The team never returned and was removed as a "future market" by the ECHL in 2014.