| Locality | Post Code |
|---|---|
| Adin, Modoc | 96006 |
| Alturas, Modoc | 96101 |
| Alturas Rancheria, Modoc | 96101 |
| California Pines, Modoc | 96101 |
| Canby, Modoc | 96015 |
| Cedarville, Modoc | 96104 |
| Davis Creek, Modoc | 96108 |
| Eagleville, Modoc | 96110 |
| Fort Bidwell, Modoc | 96112 |
| Lake City, Modoc | 96115 |
| Likely, Modoc | 96116 |
| Lookout, Modoc | 96054 |
| Willow Ranch, Modoc | 96108 |
| Xl Ranch Indian Reservation, Modoc | 96101 |