18 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 21740 | Hagerstown | 64,792 |
| 21742 | Hagerstown | 34,069 |
| 21795 | Williamsport | 10,144 |
| 21783 | Smithsburg | 9,910 |
| 21713 | Boonsboro | 9,846 |
| 21722 | Clear Spring | 6,721 |
| 21782 | Sharpsburg | 3,704 |
| 21756 | Keedysville | 3,640 |
| 21750 | Hancock | 3,417 |
| 21746 | Hagerstown | 2,361 |
| 21779 | Rohrersville | 1,311 |
| 21733 | Fairplay | 1,275 |
| 21719 | Cascade | 1,178 |
| 21734 | Funkstown | 1,076 |
| 21767 | Maugansville | 1,031 |
| 21711 | Big Pool | 929 |
| 21781 | Saint James | 25 |
| 21715 | Brownsville | 20 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 18 ZCTAs in Washington County, Maryland (US Census).