| Locality | Postal Code |
|---|---|
| Barnes City, Mahaska | 50027 |
| Beacon, Mahaska | 52534 |
| Bussey, Mahaska | 50044 |
| Cedar, Mahaska | 52543 |
| Eddyville, Mahaska | 52553 |
| Evans, Mahaska | 52577 |
| Evans Junction, Mahaska | 52534 |
| Fremont, Mahaska | 52561 |
| Keomah Village, Mahaska | 52577 |
| Lacey, Mahaska | 50207 |
| Leighton, Mahaska | 50143 |
| Lynnville, Mahaska | 50153 |
| New Sharon, Mahaska | 50207 |
| Olivet, Mahaska | 50143 |
| Oskaloosa, Mahaska | 52577 |
| Pella, Mahaska | 50219 |
| Rose Hill, Mahaska | 52586 |
| Taintor, Mahaska | 50207 |
| Tracy, Mahaska | 50256 |
| Union Mills, Mahaska | 50207 |
| University Park, Mahaska | 52595 |
| Wright, Mahaska | 52577 |