| | | Talbot County | MD | 24041 | | Easton, MD 20660 | Washington-Baltimore-Arlington,
DC-MD-VA-WV-PA 548 | Central | nonmetro county (rural) | recreation | https://maps.google.com/?q=TalbotCounty+MD |
| | | Washington County | MD | 24043 | | Hagerstown-Martinsburg,
MD-WV 25180 | Washington-Baltimore-Arlington,
DC-MD-VA-WV-PA 548 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=WashingtonCounty+MD |
| | | Baltimore city | MD | 24510 | | Baltimore-Columbia-Towson,
MD 12580 | Washington-Baltimore-Arlington,
DC-MD-VA-WV-PA 548 | Central | metro county (urban) | federal/state
government-dependent | https://maps.google.com/?q=Baltimorecity+MD |
| | | Franklin County | PA | 42055 | | Chambersburg, PA 16540 | Washington-Baltimore-Arlington,
DC-MD-VA-WV-PA 548 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=FranklinCounty+PA |
| | | Arlington County | VA | 51013 | Arlington-Alexandria-Reston,
VA-WV 11694 | Washington-Arlington-Alexandria,
DC-VA-MD-WV 47900 | Washington-Baltimore-Arlington,
DC-MD-VA-WV-PA 548 | Central | metro county (urban) | federal/state
government-dependent | https://maps.google.com/?q=ArlingtonCounty+VA |
| | | Clarke County | VA | 51043 | Arlington-Alexandria-Reston,
VA-WV 11694 | Washington-Arlington-Alexandria,
DC-VA-MD-WV 47900 | Washington-Baltimore-Arlington,
DC-MD-VA-WV-PA 548 | Outlying | metro county (urban) | nonspecialized | https://maps.google.com/?q=ClarkeCounty+VA |
| | | Culpeper County | VA | 51047 | Arlington-Alexandria-Reston,
VA-WV 11694 | Washington-Arlington-Alexandria,
DC-VA-MD-WV 47900 | Washington-Baltimore-Arlington,
DC-MD-VA-WV-PA 548 | Outlying | metro county (urban) | nonspecialized | https://maps.google.com/?q=CulpeperCounty+VA |
| | | Fairfax County | VA | 51059 | Arlington-Alexandria-Reston,
VA-WV 11694 | Washington-Arlington-Alexandria,
DC-VA-MD-WV 47900 | Washington-Baltimore-Arlington,
DC-MD-VA-WV-PA 548 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=FairfaxCounty+VA |
| | | Fauquier County | VA | 51061 | Arlington-Alexandria-Reston,
VA-WV 11694 | Washington-Arlington-Alexandria,
DC-VA-MD-WV 47900 | Washington-Baltimore-Arlington,
DC-MD-VA-WV-PA 548 | Outlying | metro county (urban) | nonspecialized | https://maps.google.com/?q=FauquierCounty+VA |
| | | Frederick County | VA | 51069 | | Winchester, VA-WV 49020 | Washington-Baltimore-Arlington,
DC-MD-VA-WV-PA 548 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=FrederickCounty+VA |