The Maryland Public Service Commission says that area code 667 will be used starting March 24th for those requesting new service. It will be assigned to all or parts of the following areas in Maryland beginning in March: Anne Arundel County, Baltimore County, Baltimore City, Calvert County, Caroline County, Carroll County, Cecil County, Dorchester County, Harford County, Howard County, Kent County, Queen Anne’s County, Somerset County, Talbot County, Wicomico County and Worcester County. The last implementation of a new area code was in 1997 with the addition of 240 and 443.