GRANTSVL — MD
Data last updated: March 10, 2026
Area Codes
Top Carriers
| Carrier | OCN | NXX Count |
|---|---|---|
| CORE COMMUNICATIONS, INC.- MD | 2593 | 1 |
| LEVEL 3 COMMUNICATIONS, LLC - MD | 6119 | 1 |
| MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | 1 |
| VERIZON MARYLAND, INC. | 9212 | 1 |
| COMMIO, LLC | 939H | 1 |