| 50401 Central Heights | 641 | Cerro Gordo County | Iowa (IA) |
| 50401 Emery | 641 | Cerro Gordo County | Iowa (IA) |
| 50401 Freeman | 641 | Cerro Gordo County | Iowa (IA) |
| 50401 Hanford | 641 | Cerro Gordo County | Iowa (IA) |
| 50401 Winnebago Heights | 641 | Cerro Gordo County | Iowa (IA) |
| 50401 Portland | 641 | Cerro Gordo County | Iowa (IA) |
| 50401 Mason City | 641 | Cerro Gordo County | Iowa (IA) |
| 50402 Mason City | 641 | Cerro Gordo County | Iowa (IA) |
| 50428 Clear Lake | 641 | Cerro Gordo County | Iowa (IA) |
| 50433 Dougherty | 641 | Cerro Gordo County | Iowa (IA) |
| 50457 Meservey | 641 | Cerro Gordo County | Iowa (IA) |
| 50464 Plymouth | 641 | Cerro Gordo County | Iowa (IA) |
| 50467 Rock Falls | 641 | Cerro Gordo County | Iowa (IA) |
| 50469 Burchinal | 641 | Cerro Gordo County | Iowa (IA) |
| 50469 Rockwell | 641 | Cerro Gordo County | Iowa (IA) |
| 50469 Cartersville | 641 | Cerro Gordo County | Iowa (IA) |
| 50477 Swaledale | 641 | Cerro Gordo County | Iowa (IA) |
| 50479 Thornton | 641 | Cerro Gordo County | Iowa (IA) |
| 50482 Ventura | 641 | Cerro Gordo County | Iowa (IA) |