| 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 |
|---|---|---|---|
| 301-859 | Prince Georges | Oxon Hill, MD | Level 3 Communications |
| 301-860 | Prince Georges | Bowie, MD | Verizon Maryland |
| 301-861 | Charles | Waldorf, MD | Level 3 Communications |
| 301-862 | Saint Marys | Lexington Park, MD | Verizon Maryland |
| 301-863 | Saint Marys | Lexington Park, MD | Verizon Maryland |
| 301-864 | Prince Georges | Hyattsville, MD | Verizon Maryland |
| 301-865 | Frederick | New Market, MD | Verizon Maryland |
| 301-866 | Saint Marys | Lexington Park, MD | Verizon Maryland |
| 301-867 | Prince Georges | Hyattsville, MD | Mcimetro Access Transmission Services LLC |
| 301-868 | Prince Georges | Clinton, MD | Verizon Maryland |
| 301-869 | Montgomery | Gaithersburg, MD | Verizon Maryland |
| 301-870 | Charles | Waldorf, MD | Verizon Maryland |
| 301-871 | Montgomery | Rockville, MD | Verizon Maryland |
| 301-872 | Saint Marys | Ridge, MD | Verizon Maryland |
| 301-873 | Montgomery | Silver Spring, MD | Cellco Partnership DBA Verizon Wireless |
| 301-874 | Frederick | Adamstown, MD | Verizon Maryland |
| 301-875 | Prince Georges | Laurel, MD | Cellco Partnership DBA Verizon Wireless |
| 301-876 | Allegany | Cumberland, MD | Level 3 Communications |
| 301-877 | Prince Georges | Clinton, MD | Verizon Maryland |
| 301-878 | Baltimore City | Baltimore, 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.