Wikipedia / List of Maryland area codes
Wikipedia / List of Maryland area codes
The state of Maryland is served in two geographically distinct numbering plan areas in the North American Numbering Plan (NANP), which are each served with three overlay area codes.
Areacode | Yearcreated | ParentNPA | Overlay | Numbering plan area |
1947 | – | 227/240/301 | Western Maryland, including its suburbs of Washington, D.C. | |
1997 | 301 | |||
2023 | 240/301 | |||
1991 | 301 | 410/443/667 | ||
1997 | 410 | |||
2012 | 410/443 |