Annapolis, MD is using an area code overlay in which area codes 410, 443 and 667 serve the same geographic area. The area code overlay was established in 1997 at which time area code 443 was created as an overlay of area code 410. In 2012 area code 667 was implemented to overlay area codes 410 and 443. Area code 410 was originally established in 1991. Ten digit dialing (area code + seven digit number) is necessary because two different homes in the same geographic area can have the same seven digit phone number but each would have a different area code.
In addition to Annapolis, MD area codes 410, 443 and 667 serve eastern Maryland, including the larger cities and communities of Annapolis, Arbutus, Arnold, Baltimore, Bel Air North, Bel Air South, Carney, Catonsville, Columbia, Crofton, Dundalk, Edgewood, Eldersburg, Elkridge, Ellicott City, Essex, Glen Burnie, Lochearn, Milford Mill, Odenton, Parkville, Perry Hall, Pikesville, Randallstown , Reisterstown, Salisbury, Severn, Severna Park, South Gate, and Towson in addition to many smaller communities.
Annapolis, MD is located in Anne Arundel County and observes the Eastern Time Zone.