Published: September 29, 2022
The western portion of Maryland, USA, currently using a Numbering Plan Area overlay complex comprising area codes 301 and 240 will, starting June 14, 2023, use a third area code 227, also covering this same geographic area. Some of the towns and cities currently served by NPAs 301/240: Bethesda, Gaithersburg, Germantown, Frederick, Silver Spring and Waldorf.
Already using overlaying area codes, the dialing plan in this part of Maryland requires 10 digit dialing for local calls and 1+10 digits for toll calls originating here. This dialing plan will not change with the new NPA's addition.
See official NANPA announcement and rate center map of the future overlay complex 301/240/227 (PDF document).
Visit area code 227 page for a list of cities served, map and other info.