Maryland Area Codes
Directory of all 6 telephone area codes assigned to Maryland.
Maryland phone numbers are served by 6 area codes operating in the Eastern timezone.Because an overlay is active, 10-digit dialing is mandatory across much of the state. No area codes in Maryland are currently flagged as high-risk scams.
Most populated prefix: area code 410 (Maryland)
All Area Codes in Maryland
Area Code 227
Frederick, Gaithersburg, Rockville, Hagerstown, College Park, Laurel, Greenbelt, Hyattsville, Cumberland, Takoma Park
Area Code 240
Frederick, Gaithersburg, Rockville, Bowie, Hagerstown, College Park, Laurel, Greenbelt, Hyattsville, Cumberland
Area Code 301
Frederick, Gaithersburg, Rockville, Bowie, Hagerstown, College Park, Laurel, Greenbelt, Hyattsville, Cumberland
Area Code 410
Baltimore, Bowie, Annapolis, Salisbury, Westminster, Aberdeen, Easton, Elkton, Havre De Grace, Cambridge
Area Code 443
Baltimore, Bowie, Annapolis, Salisbury, Westminster, Aberdeen, Easton, Elkton, Havre De Grace, Cambridge
Area Code 667
Baltimore, Bowie, Annapolis, Salisbury, Westminster, Aberdeen, Easton, Elkton, Havre De Grace, Cambridge
Major Cities Served by Maryland Area Codes
The most populous urban centers and census places covered by Maryland's area codes, ranked by population.
Maryland Area Code FAQs
Quick answers to common questions about Maryland telephone area codes.
How many area codes does Maryland have?
Maryland has 6 area codes: 227, 240, 301, 410, 443, 667.
What timezone do Maryland area codes use?
Maryland area codes operate in the Eastern timezone.
What is the most populated area code in Maryland?
Area code 410 is the most populous prefix in Maryland based on covered city population.
Which Maryland area codes share an overlay?
227 and 240, 227 and 301, 240 and 301, 410 and 443, 410 and 667, 443 and 667. Overlay codes serve the same area, which is why 10-digit dialing is required.
Are there scam area codes in Maryland?
Maryland has no area codes currently flagged as high-risk scams.
About Maryland Area Codes & Phone Dialing Rules
When placing calls within Maryland, ten-digit dialing (area code + 7-digit telephone number) is required in overlay regions where multiple area codes serve the same geographic boundaries.