Area Codes:

PREFIX COUNTY CITY
240-215-XXXX Frederick Frederick
240-225-XXXX Frederick Frederick
240-236-XXXX Frederick Frederick
240-285-XXXX Frederick Frederick
240-288-XXXX Frederick Thurmont
240-307-XXXX Frederick Emmitsburg
240-315-XXXX Frederick Frederick
240-323-XXXX Frederick Emmitsburg
240-341-XXXX Frederick Adamstown
240-344-XXXX Frederick Frederick
240-356-XXXX Frederick Frederick
240-357-XXXX Frederick Frederick
240-367-XXXX Frederick Frederick
240-379-XXXX Frederick Frederick
240-385-XXXX Frederick Myersville
240-397-XXXX Frederick Frederick
240-405-XXXX Frederick Frederick
240-409-XXXX Frederick Frederick
240-415-XXXX Frederick Frederick
240-422-XXXX Frederick Frederick
240-436-XXXX Frederick Ijamsville
240-439-XXXX Frederick Frederick
240-440-XXXX Frederick Frederick
240-446-XXXX Frederick Frederick
240-457-XXXX Frederick Frederick
240-490-XXXX Frederick Middletown
240-529-XXXX Frederick Frederick
240-566-XXXX Frederick Frederick
240-575-XXXX Frederick Frederick
240-578-XXXX Frederick Frederick
240-586-XXXX Frederick Frederick
240-608-XXXX Frederick Frederick
240-626-XXXX Frederick Frederick
240-629-XXXX Frederick Frederick
240-651-XXXX Frederick Frederick
240-674-XXXX Frederick Frederick
240-675-XXXX Frederick Myersville
240-699-XXXX Frederick Adamstown
240-772-XXXX Frederick Frederick
240-784-XXXX Frederick Myersville
301-228-XXXX Frederick Frederick
301-271-XXXX Frederick Thurmont
301-293-XXXX Frederick Myersville
301-304-XXXX Frederick Frederick
301-305-XXXX Frederick Frederick
301-360-XXXX Frederick Frederick
301-371-XXXX Frederick Middletown
301-378-XXXX Frederick Frederick
301-401-XXXX Frederick Frederick
301-418-XXXX Frederick Frederick
301-447-XXXX Frederick Emmitsburg
301-462-XXXX Frederick Myersville
301-465-XXXX Frederick Myersville
301-471-XXXX Frederick Frederick
301-473-XXXX Frederick Frederick
301-487-XXXX Frederick Myersville
301-508-XXXX Frederick Myersville
301-514-XXXX Frederick Frederick
301-524-XXXX Frederick Frederick
301-600-XXXX Frederick Frederick
301-606-XXXX Frederick Frederick
301-607-XXXX Frederick New Market
301-619-XXXX Frederick Frederick
301-620-XXXX Frederick Frederick
301-624-XXXX Frederick Frederick
301-631-XXXX Frederick Frederick
301-635-XXXX Frederick Myersville
301-639-XXXX Frederick Frederick
301-644-XXXX Frederick Frederick
301-662-XXXX Frederick Frederick
301-663-XXXX Frederick Frederick
301-667-XXXX Frederick Myersville
301-668-XXXX Frederick Frederick
301-673-XXXX Frederick Frederick
301-676-XXXX Frederick Frederick
301-682-XXXX Frederick Frederick
301-693-XXXX Frederick Frederick
301-694-XXXX Frederick Frederick
301-695-XXXX Frederick Frederick
301-696-XXXX Frederick Frederick
301-698-XXXX Frederick Frederick
301-712-XXXX Frederick Frederick
301-730-XXXX Frederick Myersville
301-748-XXXX Frederick Frederick
301-788-XXXX Frederick Frederick
301-798-XXXX Frederick New Market
301-810-XXXX Frederick Monrovia
301-815-XXXX Frederick Frederick
301-831-XXXX Frederick Adamstown
301-834-XXXX Frederick Brunswick
301-845-XXXX Frederick Walkersville
301-846-XXXX Frederick Frederick
301-865-XXXX Frederick New Market
301-874-XXXX Frederick Adamstown
301-882-XXXX Frederick New Market
301-898-XXXX Frederick Walkersville
301-964-XXXX Frederick Myersville
301-969-XXXX Frederick Brunswick
540-508-XXXX Frederick Stephens City
540-858-XXXX Frederick Gore
540-868-XXXX Frederick Stephens City
540-869-XXXX Frederick Stephens City
540-877-XXXX Frederick Winchester
540-888-XXXX Frederick Cross Junction