COLUMBIA — MD
Data last updated: August 31, 2026
Area Codes
Top Carriers
| Carrier | OCN | NXX Count |
|---|---|---|
| VERIZON MARYLAND, INC. | 9212 | 21 |
| PAETEC ITEL, LLC | 829J | 7 |
| CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD | 6395 | 6 |
| NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | 4 |
| LEVEL 3 COMMUNICATIONS, LLC - MD | 6119 | 4 |