Geographic Regions and Area Codes

Area Code 240 is located in the western part of Maryland, USA. It covers several counties—including Montgomery, Washington, and Charles—and serves major cities such as Germantown, Silver Spring, Waldorf, Frederick, Rockville, Bethesda, and Gaithersburg.

The area code is overlaid by 301 and the newly implemented 227, which became effective in June 2023 according to the Maryland Public Service Commission . Nearby area codes include 410, 443, 667 (east), 703, 571 (west, Virginia), and 202 (Washington, D.C.).

Key regions and their area codes

  • Germantown: 240, 301, 227
  • Silver Spring: 240, 301, 227
  • Waldorf: 240, 301, 227
  • Frederick: 240, 301, 227
  • Rockville: 240, 301, 227
  • Bethesda: 240, 301, 227
  • Gaithersburg: 240, 301, 227