6 area codes assigned to Maryland · Eastern Time
2 of Maryland's area codes share territory with another. Codes in the same row serve the same places, so either can reach a number there — and ten-digit dialling is required throughout.
The remaining code covers their own area: 227.
Maryland went from one area code in 1947 to 6 today. A split carves territory off its parent; an overlay sits on top of it, which is why newer codes need ten-digit dialling.
Dates from the NANPA area code report, 09/19/2026.
Maryland spans 4 LATAs — the regions a call is routed within before it becomes long-haul.
227
Maryland
Eastern Time
1,268 blocks · 38 rate centres
240
Maryland
Eastern Time
Overlay · with 301
7,874 blocks · 63 rate centres
301
Maryland
Eastern Time
Overlay · with 240
4,740 blocks · 64 rate centres
410
Maryland
Eastern Time
Overlay · with 443, 667
4,526 blocks · 103 rate centres
443
Maryland
Eastern Time
Overlay · with 410, 667
7,687 blocks · 81 rate centres
667
Maryland
Eastern Time
Overlay · with 410, 443
4,345 blocks · 102 rate centres
Maryland has more than one area code in most regions. Enter a city to see which codes serve it, or check a specific number instead.
Maryland has had 5 area codes activated as an overlay since 2021, sharing territory with an existing code rather than carving out new geography. Local calls in an overlaid region must be dialed with all ten digits. Earlier overlays are not listed here.
Maryland is served by 6 area codes in the North American Numbering Plan (NANP): 227, 240, 301, 410, 443, 667. All Maryland numbers are in the Eastern Time zone. Click any area code above to see the cities and rate centers it covers, formatted tel: link examples, and to search for available phone numbers.