| 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 |
|---|---|---|---|
| 301-489 | Prince Georges | Greenbelt, MD | Verizon Maryland |
| 301-490 | Prince Georges | Laurel, MD | Verizon Maryland |
| 301-491 | Washington | Hagerstown, MD | Uscoc Of Cumberland DBA United States Cel Md |
| 301-492 | Montgomery | Chevy Chase, MD | Verizon Maryland |
| 301-493 | Montgomery | Rockville, MD | Verizon Maryland |
| 301-494 | Prince Georges | Upper Marlboro, MD | Verizon Maryland |
| 301-495 | Montgomery | Silver Spring, MD | Verizon Maryland |
| 301-496 | Montgomery | Bethesda, MD | Verizon Maryland |
| 301-497 | Prince Georges | Laurel, MD | Verizon Maryland |
| 301-498 | Prince Georges | Laurel, MD | Verizon Maryland |
| 301-499 | Prince Georges | Capitol Heights, MD | Verizon Maryland |
| 301-500 | Montgomery | Chevy Chase, MD | Xo Maryland |
| 301-501 | Garrett | Oakland, MD | New Cingular Wireless PCS - DC |
| 301-502 | Montgomery | Silver Spring, MD | Cellco Partnership DBA Verizon Wireless |
| 301-503 | Montgomery | Bethesda, MD | New Cingular Wireless PCS - DC |
| 301-504 | Montgomery | Silver Spring, MD | Verizon Maryland |
| 301-505 | Prince Georges | Temple Hills, MD | Verizon Maryland |
| 301-506 | Prince Georges | Greenbelt, MD | Usa Mobility Wireless |
| 301-507 | Prince Georges | Greenbelt, MD | Verizon Maryland |
| 301-508 | Frederick | Myersville, MD | New Cingular Wireless PCS - DC |
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.