Original membership included all six non-MIC township schools in Indianapolis (Decatur Central, Pike, Lawrence Central, Franklin Central, Southport, and Perry Meridian high schools).

Also included were the four largest non-MIC high schools in south central Indiana at the time of conference formation: Columbus North, Bloomington South, Bloomington North, and Martinsville high schools.

Decatur Central and Martinsville left the conference after the 2005-2006 school year to join the Mid-State Conference, citing travel issues.

After Lawrence Central and Pike joined the MIC in 2013, MIC castaways Terre Haute North and South joined as trial football-only members, gaining full membership in 2014.

[1] The conference has produced a number of NBA players all drafted in the 1st round including Jared Jeffries in 2002, Sean May in 2006, Courtney Lee in 2008, Jeff Teague in 2009 and Marquis Teague in 2012.