Maryland Area Codes
Data last updated: June 25, 2026
Area Codes in Maryland
| NPA | Major Cities | Status | Exchanges | Overlay |
|---|---|---|---|---|
| 227 | Vienna, Chevy Chase, Washington | Active | 786 | Yes |
| 240 | Washington, Beltsville, Frederick | Active | 785 | Yes |
| 301 | Washington, Silver Spring, Chevy Chase | Active | 784 | Yes |
| 410 | Baltimore, Columbia, Hanover | Active | 783 | Yes |
| 443 | Baltimore, Pikesville, Columbia | Active | 785 | Yes |
| 667 | Baltimore, Salisbury, Columbia | Active | 786 | Yes |
Top Carriers in Maryland
| Carrier | OCN | NXX Count |
|---|---|---|
| VERIZON MARYLAND, INC. | 9212 | 1075 |
| OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC | 6855 | 345 |
| CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD | 6395 | 342 |
| NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | 322 |
| PAETEC ITEL, LLC | 829J | 239 |
| ONVOY, LLC - MD | 876D | 190 |
| LEVEL 3 COMMUNICATIONS, LLC - MD | 6119 | 154 |
| MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | 138 |
| CORE COMMUNICATIONS, INC.- MD | 2593 | 113 |
| BANDWIDTH.COM CLEC, LLC - MD | 071F | 86 |