7 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 52353 | Washington | 9,241 |
| 52327 | Riverside | 3,796 |
| 52356 | Wellman | 2,664 |
| 52248 | Keota | 1,675 |
| 52201 | Ainsworth | 1,148 |
| 52621 | Crawfordsville | 604 |
| 52359 | West Chester | 308 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 7 ZCTAs in Washington County, Iowa (US Census).