| | Piscataquis County | ME | 23021 | | | | | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=PiscataquisCounty+ME |
| | Sagadahoc County | ME | 23023 | | Portland-South Portland,
ME 38860 | Portland-Lewiston-South
Portland, ME 438 | Outlying | metro county (urban) | manufacturing-dependent | https://maps.google.com/?q=SagadahocCounty+ME |
| | Somerset County | ME | 23025 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=SomersetCounty+ME |
| | Waldo County | ME | 23027 | | | | | nonmetro county (rural) | recreation | https://maps.google.com/?q=WaldoCounty+ME |
| | Washington County | ME | 23029 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=WashingtonCounty+ME |
| | York County | ME | 23031 | | Portland-South Portland,
ME 38860 | Portland-Lewiston-South
Portland, ME 438 | Central | metro county (urban) | federal/state
government-dependent | https://maps.google.com/?q=YorkCounty+ME |