| District of Maryland area codes: 240 | |
|---|---|
| Country | United States |
| State/Province | Maryland |
| Major City | Baltimore |
| Time Zone | Eastern |
| Prefix | County | Primary City | Company |
|---|---|---|---|
| 240-895 | Saint Marys | Lexington Park, MD | Verizon Maryland |
| 240-897 | Prince Georges | Mount Rainier, MD | Broadwing Communications. LLC |
| 240-898 | Prince Georges | Mount Rainier, MD | Broadwing Communications. LLC |
| 240-899 | Montgomery | Bethesda, MD | Omnipoint Communications Cap Operations |
| 240-901 | Centurylink Communications LLC | ||
| 240-903 | Charles | Indian Head, MD | Comcast Phone Of Northern Maryland |
| 240-912 | Montgomery | Gaithersburg, MD | Us Lec Of Maryland |
| 240-920 | Allegany | Cumberland, MD | Level 3 Communications |
| 240-925 | Saint Marys | Leonardtown, MD | Cellco Partnership DBA Verizon Wireless |
| 240-929 | Prince Georges | Mount Rainier, MD | Cavalier East LLC |
| 240-938 | Montgomery | Ashton, MD | Omnipoint Communications Cap Operations |
| 240-949 | Prince Georges | Mount Rainier, MD | Cavalier East LLC |
| 240-964 | Allegany | Cumberland, MD | Verizon Maryland |
| 240-965 | Prince Georges | College Park, MD | Paetec Communications |
| 240-976 | Baltimore-washington Telephone (bwt) | ||
| 240-979 | Allegany | Cumberland, MD | Level 3 Communications |
| 240-986 | Charles | Nanjemoy, MD | Xo Maryland |
| 240-988 | Prince Georges | Beltsville, MD | Sprint Spectrum L.p. |
| 240-993 | Charles | Indian Head, MD | Xo Maryland |
| 240-994 | Montgomery | Rockville, MD | Cellco Partnership DBA Verizon Wireless |
There are 522 prefixes, In the code area, the major cities are Aspen Hill, MD;Bethesda, MD;Bowie, MD;Chillum, MD;. The major city is Baltimore.