| Locality | Post Code |
|---|---|
| Coralville, Johnson | 52241 |
| Cosgrove, Johnson | 52322 |
| Cou Falls, Johnson | 52338 |
| Hills, Johnson | 52235 |
| Iowa, Johnson | 52241 |
| Iowa City, Johnson | 52240, 52241, 52242, 52245, 52246 |
| Kalona, Johnson | 52247 |
| Lone Tree, Johnson | 52755 |
| Nichols, Johnson | 52766 |
| North Liberty, Johnson | 52317 |
| Oakdale, Johnson | 52241 |
| Oxford, Johnson | 52322 |
| River Junction, Johnson | 52755 |
| Riverside, Johnson | 52327 |
| Shueyville, Johnson | 52338 |
| Solon, Johnson | 52333 |
| Swisher, Johnson | 52338 |
| Tiffin, Johnson | 52340 |
| Twin View Heights, Johnson | 52333 |
| University Heights, Johnson | 52246 |
| Wellman, Johnson | 52356 |
| West Branch, Johnson | 52358 |
| Windham, Johnson | 52322 |