| ZIP Code | ZIP Code Place Name | County | ZIP Code Type |
|---|---|---|---|
| 98221 | Anacortes | Skagit County | Standard |
| 98223 | Arlington | Snohomish County | Standard |
| 98229 | Bellingham | Whatcom County | Standard |
| 98232 | Bow | Skagit County | Standard |
| 98233 | Burlington | Skagit County | Standard |
| 98235 | Clearlake | Skagit County | PO Box |
| 98237 | Concrete | Skagit County | Standard |
| 98238 | Conway | Skagit County | PO Box |
| 98241 | Darrington | Snohomish County | Standard |
| 98255 | Hamilton | Skagit County | PO Box |
| 98257 | La Conner | Skagit County | Standard |
| 98263 | Lyman | Skagit County | PO Box |
| 98267 | Marblemount | Skagit County | Standard |
| 98273 | Mount Vernon | Skagit County | Standard |
| 98274 | Mount Vernon | Skagit County | Standard |
| 98283 | Rockport | Skagit County | Standard |
| 98284 | Sedro Woolley | Skagit County | Standard |