Maryland Area Codes: Complete List With Cities Served
Maryland is served by 6 area codes. Growth in phone lines has pushed the state to add new codes over the years, often as overlays on existing regions.
Maryland area code list
| Area code | Main places served |
|---|---|
| 227 | Silver Spring, Bethesda, Hyattsville and Gaithersburg |
| 240 | Silver Spring, Bethesda, Gaithersburg and Rockville |
| 301 | Silver Spring, Bethesda, Hyattsville and Gaithersburg |
| 410 | Baltimore, Annapolis, Towson and Salisbury |
| 443 | Baltimore, Annapolis, Towson and Columbia |
| 667 | Baltimore, Annapolis, Towson and Columbia |
Place names come from ZIP code records linked to each area code, so they show where a code is most common rather than exact boundaries.
Area codes by major city
| City | Area codes |
|---|---|
| Baltimore | 410, 443, 667 |
| Silver Spring | 227, 240, 301 |
| Annapolis | 410, 443, 667 |
| Hyattsville | 227, 240, 301 |
| Bowie | 227, 240, 301, 410, 443, 667 |
| Frederick | 227, 240, 301 |
| Gaithersburg | 227, 240, 301, 410, 443, 667 |
| Laurel | 227, 240, 301, 410, 443, 667 |
| Rockville | 227, 240, 301 |
| Bethesda | 227, 240, 301 |
| Columbia | 227, 240, 301, 410, 443, 667 |
| Waldorf | 227, 240, 301 |
| Bel Air | 410, 443, 667 |
| Ellicott City | 410, 443, 667 |
| Germantown | 227, 240, 301 |
How to format a Maryland phone number
US numbers have ten digits: the area code, a three-digit exchange and a four-digit line number. A Maryland number is written as (227) 555-0123 for display, or +12275550123 in E.164 format for storage.
Safe numbers for testing
The range 555-0100 to 555-0199 is reserved for fictional use in every area code. Our generator combines these with real local area codes, so test data looks right without reaching a real person.
Why overlays matter for your forms
With overlays, you cannot guess a city from its area code alone, and people who move keep their numbers. Use area codes for display and formatting, not for location checks.
Create realistic Maryland addresses for testing, with real cities, counties and ZIP codes.
Generate Maryland addresses