| | Adair County | IA | 19001 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=AdairCounty+IA |
| | Adams County | IA | 19003 | | | | | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=AdamsCounty+IA |
| | Allamakee County | IA | 19005 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=AllamakeeCounty+IA |
| | Appanoose County | IA | 19007 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=AppanooseCounty+IA |
| | Audubon County | IA | 19009 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=AudubonCounty+IA |
| | Benton County | IA | 19011 | | Cedar Rapids, IA 16300 | Cedar Rapids-Iowa City,
IA 168 | Outlying | metro county (urban) | nonspecialized | https://maps.google.com/?q=BentonCounty+IA |
| | Black Hawk County | IA | 19013 | | Waterloo-Cedar Falls, IA 47940 | | Central | metro county (urban) | manufacturing-dependent | https://maps.google.com/?q=BlackHawkCounty+IA |
| | Boone County | IA | 19015 | | Ames, IA 11180 | Des Moines-West Des
Moines-Ames, IA 218 | Outlying | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=BooneCounty+Iowa |
| | Bremer County | IA | 19017 | | Waterloo-Cedar Falls, IA 47940 | | Outlying | metro county (urban) | nonspecialized | https://maps.google.com/?q=BremerCounty+IA |
| | Buchanan County | IA | 19019 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=BuchananCounty+IA |