geographic
What is the 301 area code and which Maryland cities does it cover?
The 301 area code covers Maryland DC suburbs including Bethesda, Silver Spring, Rockville, Gaithersburg, Germantown, Potomac, Olney, Takoma Park, Laurel, Columbia, Annapolis, Frederick, and Hagerstown.
## What is the 301 area code?
The 301 area code is one of the original North American Numbering Plan area codes assigned in 1947, covering the Maryland suburbs of Washington DC. When Maryland grew, the 240 area code was overlaid on the same geography in 1997.
The 301/240 region covers a 25-city area centered on Montgomery County, Frederick County, Prince George's County, Anne Arundel County, Howard County, and Washington County.
Frequently asked questions
What is the 301 area code?
The 301 area code is one of the original North American Numbering Plan area codes assigned in 1947, covering the Maryland suburbs of Washington DC. When Maryland grew, the 240 area code was overlaid on the same geography in 1997.
301 cities by county
**Montgomery County:** Bethesda, Silver Spring, Rockville, Gaithersburg, Germantown, Potomac, Olney, Takoma Park, Chevy Chase, Wheaton, Kensington, Damascus
240 area code
The 240 area code was overlaid on the same 301 region in 1997. Both 301 and 240 are used interchangeably.
Why 301 and not DC
202 (with 771 overlay) covers Washington DC. 301/240 covers only Maryland suburbs of DC.
Related resources
- Browse all Maryland cities: https://301businessdirectory.com/cities - Free editor content: https://301businessdirectory.com/articles - Maryland SDAT: https://dat.maryland.gov
Also from the 301 Business Directory network
301 is part of the Good AiDeas network of small-business directories. If you're researching service businesses across the DC area, these sister sites cover the rest: