The 301 area code serves western Maryland and the Washington, D.C. suburbs. One of the original area codes assigned in 1947, 301 covers the populous Montgomery and Prince George’s counties, the biotechnology corridor along Interstate 270, and the western reaches of the state out to Hagerstown and Cumberland.
Quick Summary of the 301 Area Code
| Area Code | 301 |
| State | Maryland (MD) |
| Region | Western Maryland & Washington, D.C. Suburbs |
| Major Cities | Rockville, Bethesda, Silver Spring, Frederick, Gaithersburg, Germantown, Hagerstown, Bowie, Waldorf, College Park |
| Time Zone | Eastern Time (ET) – EST / EDT |
| Dialing Format | 10-digit dialing required |
Geographic Coverage
The 301 area code spans a large portion of Maryland, from the inner Washington suburbs of Silver Spring, Bethesda, and College Park, through the Montgomery County cities of Rockville, Gaithersburg, and Germantown, north to Frederick, and west across the Appalachian panhandle to Hagerstown and Cumberland. To the south it reaches the Prince George’s and Charles County communities of Bowie and Waldorf. It shares its entire footprint with the 240 overlay.
Time Zone
The 301 area code observes Eastern Time (ET). Clocks follow Eastern Standard Time (UTC−5) in winter and shift to Eastern Daylight Time (UTC−4) from mid-March through early November. If you are coordinating a call from the West Coast, remember that this region is three hours ahead of Pacific Time, so a 9:00 AM call in California reaches a 301 number at 12:00 PM local time.
Tip: Business hours across the 301 region generally run 9:00 AM to 5:00 PM Eastern Time, Monday through Friday.
How to Dial a 301 Number
Because area code 301 operates as part of an overlay, 10-digit dialing is mandatory for every local and long-distance call. You must dial the full 10-digit number (301 + the seven-digit line number) even when calling a neighbor across the street. For international callers, dial your country’s exit code, then +1 (the North American country code), then 301, followed by the seven-digit local number.
Scam Alerts for the 301 Area Code
Like every U.S. area code, 301 has been used by scammers who spoof local numbers to appear trustworthy. Residents in Rockville, Bethesda, Silver Spring, Frederick, Gaithersburg, Germantown, Hagerstown, Bowie, Waldorf, College Park should stay alert to the following common tactics:
| Scam Type | What to Watch For |
|---|---|
| IRS / Tax Scams | Callers claiming you owe back taxes and threatening arrest unless you pay immediately. |
| Utility Shut-off | Fake BGE or Pepco reps demanding payment to avoid disconnection. |
| Federal Job Scam | Fake “government hiring” calls targeting DC-area job seekers for personal data. |
| Bank Fraud Alerts | Robocalls impersonating your bank about “suspicious activity” to phish account details. |
If you receive a suspicious call from a 301 number, take these steps to protect yourself:
- Do not share personal information such as Social Security numbers, bank details, or passwords over the phone.
- Hang up and verify by calling the organization back using an official number from its website.
- Report the call to the FTC at reportfraud.ftc.gov and to the Maryland Attorney General’s Office.
- Block the number and consider registering with the National Do Not Call Registry.
Red Flag: Legitimate agencies such as the IRS, Social Security Administration, or your utility company (BGE, Pepco, or Potomac Edison) will never demand immediate payment by gift card, wire transfer, or cryptocurrency. Any 301 caller making such a demand is a scammer.
History and Economy of the 301 Region
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Area code 301 is one of the original 86 codes created in 1947, and it once covered the entire state of Maryland. As the state grew, eastern Maryland was split off into the 410 area code in 1991, and in 1997 the 240 overlay was added on top of the remaining 301 territory to satisfy soaring demand for numbers in the Washington suburbs. The regional economy is anchored by the federal government and the sciences: Montgomery County hosts the National Institutes of Health, the Food and Drug Administration, and the National Institute of Standards and Technology, and the I-270 corridor is one of the nation’s leading biotechnology hubs. Frederick blends historic downtown charm with a growing life-sciences sector, while Hagerstown and Cumberland anchor the more rural western panhandle.
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Looking Up a 301 Number
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To identify a 301 caller, use a reverse phone lookup service or search the full 10-digit number online. Many government offices, hospitals, and businesses in the DC suburbs list their 301 numbers publicly, so a quick search often confirms a legitimate caller. For unknown numbers, let the call go to voicemail – genuine callers usually leave a message.
Nearby & Related Area Codes
Maryland is served by several area codes. If you are researching 301, these neighboring and overlay codes are worth knowing:
- 240 – DC suburbs overlay (same region)
- 410 – Baltimore & Eastern Maryland
- 443 – Baltimore overlay
- 667 – Baltimore overlay
You can also browse our full directory of Maryland area codes for more regional guides.
↑ See the complete list of All US Area Codes by State – every area code across all 50 states in one directory.
Explore Neighboring States
Researching area codes just across the state line? Start with these codes in the states that border Maryland:
- Pennsylvania – area code 215
- Delaware – area code 302
- Virginia – area code 804
- West Virginia – area code 304
Frequently Asked Questions
Where is the 301 area code located?
The 301 area code covers western Maryland and the Washington, D.C. suburbs, including Montgomery County (Rockville, Bethesda, Silver Spring), Frederick, and the western panhandle out to Hagerstown.
Do I need to dial 10 digits for 301?
Yes. Because 301 shares an overlay with the 240 area code, you must dial all 10 digits for every local call.
What time zone is the 301 area code in?
The 301 area code is in the Eastern Time Zone (EST/EDT).
Is 301 the same area as 240?
Yes. 240 is an overlay of 301, so both codes serve the exact same region of Maryland.
Related 301 Guides
- Is a 301 call safe? Read Is area code 301 a scam? Spam & safety guide.
- Local coverage: see the Frederick area code guide.
- Worried about spam or robocalls? Browse our Scam Alerts directory.