| | | Martin County | IN | 18101 | | | | | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=MartinCounty+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 |
| | | Newton County | IN | 18111 | Lake County-Porter
County-Jasper County, IN 29414 | Chicago-Naperville-Elgin,
IL-IN 16980 | Chicago-Naperville,
IL-IN-WI 176 | Outlying | metro county (urban) | nonspecialized | https://maps.google.com/?q=NewtonCounty+Indiana |
| | | 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 |
| | | Ohio County | IN | 18115 | | Cincinnati, OH-KY-IN 17140 | Cincinnati-Wilmington,
OH-KY-IN 178 | Outlying | metro county (urban) | recreation | https://maps.google.com/?q=OhioCounty+IN |
| | | Orange County | IN | 18117 | | | | | nonmetro county (rural) | recreation | https://maps.google.com/?q=OrangeCounty+IN |
| | | Owen County | IN | 18119 | | Bloomington, IN 14020 | Bloomington-Bedford, IN 144 | Outlying | metro county (urban) | manufacturing-dependent | https://maps.google.com/?q=OwenCounty+IN |
