| District of Maryland area codes: 301 | |
|---|---|
| Country | United States |
| State/Province | Maryland |
| Major City | Baltimore |
| Time Zone | Eastern (UTC-05:00) |
| Prefix | County | Primary City | Company |
|---|---|---|---|
| 301-469 | Montgomery | Bethesda, MD | Verizon Maryland |
| 301-470 | Prince Georges | Laurel, MD | Verizon Maryland |
| 301-471 | Frederick | Frederick, MD | Cellco Partnership DBA Verizon Wireless |
| 301-472 | Saint Marys | Mechanicsville, MD | Verizon Maryland |
| 301-473 | Frederick | Frederick, MD | Verizon Maryland |
| 301-474 | Prince Georges | Greenbelt, MD | Verizon Maryland |
| 301-475 | Saint Marys | Leonardtown, MD | Verizon Maryland |
| 301-476 | Montgomery | Silver Spring, MD | Verizon Maryland |
| 301-477 | Prince Georges | College Park, MD | Comcast Phone Of Northern Maryland |
| 301-478 | Allegany | Oldtown, MD | Verizon Maryland |
| 301-479 | Prince Georges | College Park, MD | Mci Worldcom Communications |
| 301-480 | Montgomery | Bethesda, MD | Verizon Maryland |
| 301-481 | Saint Marys | Leonardtown, MD | Cellco Partnership DBA Verizon Wireless |
| 301-482 | Montgomery | Damascus, MD | Verizon Maryland |
| 301-483 | Prince Georges | Laurel, MD | Verizon Maryland |
| 301-484 | Prince Georges | Oxon Hill, MD | Comcast Phone Of Northern Maryland |
| 301-485 | Prince Georges | Oxon Hill, MD | Comcast Phone Of Northern Maryland |
| 301-486 | Prince Georges | Greenbelt, MD | Verizon Maryland |
| 301-487 | Frederick | Myersville, MD | Verizon Maryland |
| 301-488 | Prince Georges | Greenbelt, MD | Verizon Maryland |
There are 775 prefixes, In the code area, the major cities are Aspen Hill, MD;Bethesda, MD;Bowie, MD;Chillum, MD;. The major city is Baltimore.