Area Code 410

410 is the area code for the eastern half of Maryland, including the city of Baltimore, Baltimore County, Anne Arundel, Calvert, Carroll, Harford and Howard counties. 410 also covers the Eastern Shore counties of Caroline, Cecil, Dorchester, Kent, Queen Anne’s, Somerset, Talbot, Wicomico, and Worcester. 410 is overlaid by the 443 area code, which is mostly assigned to cell phones.