240 Area Code
Western Maryland (suburban DC), Maryland
Area code 240 is located in Western Maryland (suburban DC), Maryland. It covers Rockville, Gaithersburg, and surrounding areas in the Eastern time zone (UTC-5). Administered by NANPA.
Where is area code 240?
Area code 240 is located in Western Maryland (suburban DC), Maryland. It covers Rockville, Gaithersburg, and surrounding areas in the Eastern time zone (UTC-5).
Cities Covered by Area Code 240
Area code 240 primarily serves the Western Maryland (suburban DC) area of Maryland. The exact coverage includes Rockville, Gaithersburg, and Bethesda, along with surrounding communities and suburbs.
Time Zone
Eastern Time — UTC-5
Area code 240 operates in the Eastern Time Zone. When calling 240 numbers from a different time zone, be sure to account for the time difference to reach people during business hours.
About Area Code 240
Area code 240 was introduced in 1997 as a geographic area code serving Western Maryland (suburban DC), Maryland. It remains the primary area code for this region. Area codes are administered by NANPA (North American Numbering Plan Administration), the organization responsible for managing phone number resources in the US and Canada.