10 ZIP Codes
| Zip Code | City | Population ↓ |
|---|---|---|
| 64506 | Saint Joseph | 21,461 |
| 64507 | Saint Joseph | 13,991 |
| 64503 | Saint Joseph | 11,954 |
| 64501 | Saint Joseph | 10,689 |
| 64504 | Saint Joseph | 10,068 |
| 64401 | Agency | 1,757 |
| 64443 | Easton | 1,249 |
| 64484 | Rushville | 940 |
| 64448 | Faucett | 912 |
| 64440 | De Kalb | 900 |
The data shown reflect ZCTAs from the US Census. As of 2025, there are 10 ZCTAs in Buchanan County, Missouri (US Census).