Member schools are classified into four classes based on enrollment, ranging from the smallest, 1A, to the largest, 4A.

The northern district is composed of Adams, Allen, Cass, DeKalb, Elkhart, Fulton, Huntington, Jasper, Kosciusko, LaGrange, Lake, LaPorte, Marshall, Miami, Newton, Noble, Porter, Pulaski, St. Joseph, Starke, Steuben, Wabash, Wells and Whitley counties.

The central district is composed of Benton, Blackford, Boone, Clinton, Carroll, Delaware, Fountain, Grant, Hamilton, Hancock, Hendricks, Henry, Howard, Jay, Madison, Marion, Montgomery, Parke, Putnam, Randolph, Tippecanoe, Tipton, Vermillion, Warren, and White counties.

The southern district is composed of Bartholomew, Brown, Clark, Clay, Crawford, Daviess, Dearborn, Decatur, Dubois, Fayette, Floyd, Franklin, Gibson, Greene, Harrison, Jackson, Jefferson, Jennings, Johnson, Knox, Lawrence, Martin, Monroe, Morgan, Ohio, Orange, Owen, Perry, Pike, Posey, Ripley, Rush, Scott, Shelby, Spencer, Sullivan, Switzerland, Union, Vanderburgh, Vigo, Warrick, Washington and Wayne counties.

[3] In the regular season, most of the member-schools' sports activities are governed by Indiana's high school athletic conferences.