Where Is Area Code 240?
Area code 240 serves western and southern Maryland, including Aspen Hill in Montgomery County and suburbs in the Washington, D.C., metropolitan area. It is a geographic code that identifies a Maryland calling region rather than a toll-free service.
The 240 and 301 calling region includes Montgomery, Prince George’s, Frederick, Washington, Allegany, Garrett, Charles, Calvert, and St. Mary’s counties. Major communities include Bethesda, Gaithersburg, Rockville, Silver Spring, Bowie, Frederick, Hagerstown, Cumberland, Waldorf, and Lexington Park.
Notable geographic features include the Potomac River, the Appalachian Mountains in western Maryland, and the Chesapeake and Ohio Canal National Historical Park. The region also includes the National Institutes of Health campus in Bethesda and the University of Maryland, College Park.
Cities and Communities in the 240 Area Code
- Aspen Hill, Montgomery County
- Bethesda, Montgomery County
- Gaithersburg, Montgomery County
- Germantown, Montgomery County
- Rockville, Montgomery County
- Silver Spring, Montgomery County
- Takoma Park, Montgomery County
- Bowie, Prince George’s County
- College Park, Prince George’s County
- Greenbelt, Prince George’s County
- Hyattsville, Prince George’s County
- Upper Marlboro, Prince George’s County
- Frederick, Frederick County
- Brunswick, Frederick County
- Hagerstown, Washington County
- Cumberland, Allegany County
- Oakland, Garrett County
- Waldorf, Charles County
- La Plata, Charles County
- Prince Frederick, Calvert County
- Lexington Park, St. Mary’s County
- Leonardtown, St. Mary’s County
History of Area Code 240
Area code 240 was established on June 1, 1997, as an overlay for area code 301. Maryland’s original 301 area code dates to 1947, and area code 410 split from 301 in 1991 to serve Baltimore and much of eastern Maryland.
The 240 overlay added new telephone numbers without removing existing 301 numbers from the region. Area code 227 became a second overlay for the same 240 and 301 territory on June 14, 2022. These codes serve the same broad geographic region rather than separate sections of Maryland.
Key Facts About Area Code 240
- Area code 240 is a geographic area code in Maryland, in the U.S. Census South Atlantic region.
- Aspen Hill is the primary locality associated with area code 240, and it is in Montgomery County.
- Area code 240 is in the Eastern Time zone.
- Area code 240 entered service on June 1, 1997, as an overlay of area code 301.
- Area code 240 is an overlay code, not Maryland’s original area code and not a geographic split.
- Area code 227 became a second overlay for the 240 and 301 region on June 14, 2022.
- The National Institutes of Health main campus is located in Bethesda, Montgomery County, within the 240 and 301 calling region.
- The University of Maryland, College Park, is located in College Park, Prince George’s County, within the same calling region.
Frequently Asked Questions
What state is area code 240 in?
Area code 240 is in Maryland.
What major cities use area code 240?
Major cities and communities using area code 240 include Aspen Hill, Bethesda, Gaithersburg, Rockville, Silver Spring, Bowie, Frederick, Hagerstown, Cumberland, Waldorf, and Lexington Park.
What time zone is area code 240 in?
Area code 240 is in Eastern Time.
Is area code 240 a toll-free number?
No. Area code 240 is a geographic area code, not a toll-free number.