Within the ICTFL structure, the state of Illinois is divided into five regions (map below). The regions are:
Region One: Region one serves the counties of Cook, Du Page, Lake, and Will.
Region Two: Region two serves the counties of Boone, Bureau, Carroll, DeKalb, Grundy, Henry, Jo Daviess, Kane, Kendall, LaSalle, Lee, Marshall, McHenry, Ogle, Putnam, Rock Island, Stark, Stephenson, Winnebago and Whiteside.
Region Three: Region three serves the counties of Adams, Brown, Calhoun, Cass, Christian, Fulton, Greene, Hancock, Henderson, Jersey, Knox, Logan, Macoupin, Mason, McDonough, Menard, Mercer, Montgomery, Morgan, Peoria, Pike, Sangamon, Scott, Schuyler, Tazewell and Warren.
Region Four: Region four serves the counties of Champaign, Clark, Coles, Cumberland, DeWitt, Douglas, Edgar, Ford, Iroquois, Kankakee, Livingston, Macon, Moultrie, McLean, Piatt, Shelby, Vermillion and Woodford.
Region Five: Region five serves the counties of Alexander, Bond, Clay, Clinton, Crawford, Edwards, Effingham, Fayette, Franklin, Gallatin, Hamilton, Hardin, Jackson, Jasper, Jefferson, Johnson, Lawrence, Madison, Massac, Monroe, Perry, Pope, Pulaski, Randolph, Richland, St. Clair, Saline, Union, Wabash, Washington, Wayne, White, and Williamson.