MASON CITY — IA
Data last updated: March 10, 2026
Area Codes
Top Carriers
| Carrier | OCN | NXX Count |
|---|---|---|
| QWEST CORPORATION | 9631 | 7 |
| T-MOBILE USA, INC. | 6529 | 4 |
| UNITED STATES CELLULAR - IA | 6266 | 3 |
| CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IA | 6570 | 2 |
| NORTHLAND COMMUNICATIONS, INC. - IA | 068H | 1 |