Maryland Area Code Directory Information

The area codes which serve Maryland’s part of the Greater Washington, D.C. metro area, southern Maryland portions and all points northwest of Washington are 240 and 301. Cumberland, Frederick, Hagerstown and Gaithersburg are some of the communities which fall under these area codes. One of the original area codes established in 1947 is 301. Area code 301 was exclusive for the entire state of Maryland until 410 came into existence on October 6, 1991. 240 which is the overlay area code for Maryland, was introduced on June 1, 1997.

These area codes serve some of the counties of Maryland, which includes: Allegany, Charles, Frederick, Garrett, Howard, Montgomery, Prince George’s, St. Mary’s and Washington.

To make a local call, you will need 10-digit dialing, which includes area code with the number and leading “1” is not required.

The area code 227 is expected to be overlaid with area codes 240 and 301 and it is scheduled to be overlaid in the coming future to provide additional assignable numbers.

The telephone area codes which serve the entire area of the eastern half of the state of Maryland are 410 and 443. The area code 410 is the main area code, while the overlay area code is 443, and it is used mainly for cell phones. Before the introduction of the area code 410 and 443, the only area code that served the entire state of Maryland was 301. It was in the year 1991 when the Maryland government came up with the plan to establish and add a second area code in the state which was 410. The authorities decided that the new area code 410 will serve the areas from Baltimore metropolitan to the eastern shore and southern and the western parts of Maryland and the Washington D.C. suburbs would remain with the area code 301. It was on July 1, 1997 when the 443 area code came into effect.

The area code 443 serves the counties of Maryland which includes:

Baltimore metropolitan area: the independent city of Baltimore, Anne Arundel, Baltimore, Calvert, Carroll, Harford and Howard counties.

On the eastern shore it covers Dorchester, Caroline, Cecil Kent, Queen Anne’s, Somerset, Talbot, Wicomico and Worcester counties.

Maryland Area Codes

Area Code 240

The Area code 240 covers 12 counties and it has a population of around 1,075,439. The counties which are served by this area code are: Allegany, Anne Arundel, Baltimore, Calvert, Charles, Frederick, Garrett, Howard, Montgomery, Prince Georges, Saint Marys and Washington. It covers 92 cities and it has 455 exchanges.

Area Code 301

The Area code 301 covers 17 counties and it has a population of around 2,587,425. The counties which are covered by 301 are: Alexandria City, Allegany, Anne Arundel, Baltimore, Baltimore City, Calvert, Carroll, Charles, District of Columbia, Frederick, Garrett, Howard, Montgomery, Newport News City, Prince Georges, Saint Marys and Washington. It also covers 218 cities and it has got 775 exchanges.

Area Code 410

The Area code 410 covers 19 counties and it has a population of around 3,039,848. The counties which fall under this area code are: Anne Arundel, Baltimore, Baltimore City, Calvert, Caroline, Carroll, Cecil, Dorchester, Frederick, Harford, Howard, Kent, Montgomery, Prince Georges, Queen Annes, Somerset, Talbot, Wicomico and Worcester. Area Code 410 covers 248 cities and it has 782 exchanges.

Area Code 443

The Area code 443 covers 18 counties and it has a population of around 1,592,514. The counties which fall under this area code are: Anne Arundel, Baltimore, Baltimore City, Calvert, Caroline, Carroll, Cecil, Dorchester, Frederick, Harford, Howard, Kent, Prince Georges, Queen Annes, Somerset, Talbot, Wicomico and Worcester. This area code also covers 119 cities and it has 711 exchanges.