Area Code 410

Maryland consists of the red and blue areas. The blue area indicates area codes 410 and 443.
Area codes 410 and 443 are telephone area codes serving the eastern half of the U.S. state of Maryland. The 410 area code is the main area code, while the 443 code is an overlay code, that was primarily used with cell phones and CLEC carriers such as Comcast or Cavalier Telephone when introduced but has since become universal in its carrier availability. Before these area codes were created, all of Maryland was served by area code 301. In 1991, the Maryland government came up with a plan to add a second area code, the 410 code, to the state. They eventually decided that the Baltimore metropolitan area and the Eastern Shore area would get the new area code, and the western and southern parts of Maryland and the Washington, D.C. suburbs would remain with the 301 area code. The 443 overlay code took effect on July 1, 1997.

The counties served by this area code include:

In the Baltimore metropolitan area:
*The independent city of Baltimore
*Anne Arundel County
*Baltimore County
*Calvert County
*Carroll County
*Harford County
*Howard County

On the Eastern Shore:
*Caroline County
*Cecil County
*Dorchester County
*Kent County
*Queen Anne's County
*Somerset County
*Talbot County
*Wicomico County
*Worcester County

Numbers starting with 410