Annapolis Time| City | Area Code | Dialing Code |
| Annapolis | 410 | +1 410 |
| Baltimore | 410 | +1 410 |
| Bethesda | 301 | +1 301 |
| Bowie | 301 | +1 301 |
| Catonsville | 443 | +1 443 |
| Clinton | 301 | +1 301 |
| Columbia | 803 | +1 803 |
| Dundalk | 443 | +1 443 |
| Ellicott City | 443 | +1 443 |
| Essex | 443 | +1 443 |
| Frederick | 301 | +1 301 |
| Gaithersburg | 240 | +1 240 |
| Germantown | 301 | +1 301 |
| Glen Burnie | 443 | +1 443 |
| Hagerstown | 301 | +1 301 |
| Montgomery Village | 301 | +1 301 |
| Olney | 301 | +1 301 |
| Parkville | 443 | +1 443 |
| Perry Hall | 410 | +1 410 |
| Pikesville | 443 | +1 443 |
| Potomac | 301 | +1 301 |
| Randallstown | 410 | +1 410 |
| Rockville | 301 | +1 301 |
| Severn | 443 | +1 443 |
| Severna Park | 443 | +1 443 |
| Silver Spring | 301 | +1 301 |
| Towson | 410 | +1 410 |