| Locality | Post Code |
|---|---|
| Fort Atkinson, Jefferson | 53538 |
| Helenville, Jefferson | 53137 |
| Ixonia, Jefferson | 53036 |
| Jefferson, Jefferson | 53549 |
| Johnson Creek, Jefferson | 53038, 53094 |
| Lake Mills, Jefferson | 53551 |
| Palmyra, Jefferson | 53156 |
| Sullivan, Jefferson | 53178 |
| Waterloo, Jefferson | 53594 |
| Watertown, Jefferson | 53094 |