| 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 |
|---|---|---|---|
| 301-262 | Prince Georges | Bowie, MD | Verizon Maryland |
| 301-263 | Montgomery | Glen Echo, MD | Verizon Maryland |
| 301-264 | Allegany | Mount Savage, MD | Verizon Maryland |
| 301-265 | Prince Georges | Fort Washington, MD | Verizon Maryland |
| 301-266 | Charles | Waldorf, MD | New Cingular Wireless PCS - DC |
| 301-267 | Prince Georges | Greenbelt, MD | Sprint Spectrum L.p. |
| 301-268 | Allegany | Cumberland, MD | Uscoc Of Cumberland DBA United States Cel Md |
| 301-270 | Prince Georges | Hyattsville, MD | Verizon Maryland |
| 301-271 | Frederick | Thurmont, MD | Verizon Maryland |
| 301-272 | Montgomery | Rockville, MD | Mci Worldcom Communications |
| 301-273 | Montgomery | Silver Spring, MD | Mci Worldcom Communications |
| 301-274 | Charles | Hughesville, MD | Verizon Maryland |
| 301-275 | Montgomery | Bethesda, MD | New Cingular Wireless PCS - DC |
| 301-276 | Prince Georges | Hyattsville, MD | Mci Worldcom Communications |
| 301-277 | Prince Georges | Hyattsville, MD | Verizon Maryland |
| 301-278 | Prince Georges | Mount Rainier, MD | Mci Worldcom Communications |
| 301-279 | Montgomery | Rockville, MD | Verizon Maryland |
| 301-280 | Montgomery | Chevy Chase, MD | Verizon Maryland |
| 301-281 | Prince Georges | Oxon Hill, MD | Mci Worldcom Communications |
| 301-282 | Montgomery | Silver Spring, 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.