| Locality | Post Code |
|---|---|
| Clay, Marion | 63401 |
| Ely, Marion | 63461 |
| Hannibal, Marion | 63401 |
| Huntington, Marion | 63401 |
| Ilasco, Marion | 63401 |
| Maywood, Marion | 63454 |
| Monkey Run, Marion | 63401 |
| Monroe City, Marion | 63456 |
| Palmyra, Marion | 63461 |
| Philadelphia, Marion | 63463 |
| Rensselaer, Marion | 63401 |
| South River, Marion | 63461 |
| Spalding, Marion | 63401 |
| Taylor, Marion | 63471 |
| West Ely, Marion | 63401 |
| West Quincy, Marion | 63471 |
| Withers Mill, Marion | 63401, 63461 |
| Woodland, Marion | 63461 |