| | Lake County | IN | 18089 | Lake County-Porter
County-Jasper County, IN 29414 | Chicago-Naperville-Elgin,
IL-IN 16980 | Chicago-Naperville,
IL-IN-WI 176 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=LakeCounty+Indiana |
| | LaPorte County | IN | 18091 | | Michigan City-La Porte,
IN 33140 | Chicago-Naperville,
IL-IN-WI 176 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=LaPorteCounty+IN |
| | Lawrence County | IN | 18093 | | Bedford, IN 13260 | Bloomington-Bedford, IN 144 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=LawrenceCounty+IN |
| | Marion County | IN | 18097 | | Indianapolis-Carmel-Greenwood,
IN 26900 | Indianapolis-Carmel-Muncie,
IN 294 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=MarionCounty+IN |
| | Marshall County | IN | 18099 | | Plymouth, IN 38500 | South
Bend-Elkhart-Mishawaka,
IN-MI 515 | Central | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=MarshallCounty+IN |
| | Miami County | IN | 18103 | | Peru, IN 37940 | Indianapolis-Carmel-Muncie,
IN 294 | Central | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=MiamiCounty+IN |
| | Monroe County | IN | 18105 | | Bloomington, IN 14020 | Bloomington-Bedford, IN 144 | Central | metro county (urban) | federal/state
government-dependent | https://maps.google.com/?q=MonroeCounty+IN |
| | Montgomery County | IN | 18107 | | Crawfordsville, IN 18820 | Indianapolis-Carmel-Muncie,
IN 294 | Central | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=MontgomeryCounty+IN |
| | Morgan County | IN | 18109 | | Indianapolis-Carmel-Greenwood,
IN 26900 | Indianapolis-Carmel-Muncie,
IN 294 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=MorganCounty+IN |
| | Noble County | IN | 18113 | | Kendallville, IN 28340 | Fort
Wayne-Huntington-Auburn,
IN 258 | Central | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=NobleCounty+IN |