ARGRGBSNIS — MD
Data last updated: March 10, 2026
Area Codes
Top Carriers
| Carrier | OCN | NXX Count |
|---|---|---|
| VERIZON MARYLAND, INC. | 9212 | 5 |
| ONVOY, LLC - MD | 876D | 3 |
| LEVEL 3 COMMUNICATIONS, LLC - MD | 6119 | 2 |
| MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | 2 |
| MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | 1 |