Massachusetts · Eastern Time
617 Area Code
Area code 617 is in Massachusetts, serving Boston and its closest neighbors including Cambridge, Quincy and Newton. It is in the Eastern Time zone. It shares its territory with overlay code 857, so 10-digit dialing is required.
Last updated October 1, 2026 · Source: NANPA
Where is the 617 area code?
617 is a Massachusetts area code covering Boston and its closest neighbors including Cambridge, Quincy and Newton. In the wider directory it sits in the Northeast region.
Cities in the 617 area code
- Boston
- Cambridge
- Quincy
- Newton
- Somerville
- Brookline
- Watertown
- Chelsea
- Everett
- Belmont
- Milton
- Winthrop
Counties served by 617
Suffolk County, Middlesex County and Norfolk County.
617 overlay codes and dialing
The 617 territory is covered by an overlay of 2 area codes: 617, 857. All of them serve the same geographic area, and the original code is 617. Because more than one code covers the same ground, 10-digit dialing is mandatory — you must dial the area code for every local call. New phone lines may be assigned any of these codes.
History of the 617 area code
617 is one of the original area codes assigned in 1947, when AT&T and Bell Laboratories created the North American Numbering Plan and divided the country into the first 86 numbering plan areas. It has served the Boston area ever since, with 857 later added as an overlay to supply more numbers.
Is 617 a scam or spam risk?
617 is a legitimate geographic area code, not a premium or toll line, so a call from it costs you nothing extra. That said, scammers frequently spoof real local area codes to look familiar on caller ID. A genuine 617 number on your screen is no guarantee the caller is in Boston, MA or trustworthy. See spam & scam-risk area codes for how spoofing works and how to respond.
Other Massachusetts area codes
Explore more
See every code in Massachusetts, compare codes across the Northeast region, or view all Eastern Time codes. You can also browse the 6XX block or the complete numeric list of US area codes.
New to how this all works? Start with how area codes work, then read up on overlays, 10-digit dialing, and spam & scam-risk codes. To check another number, use the area code lookup tool.
Quick answers
617 area code FAQ
Where is the 617 area code?
The 617 area code is in Massachusetts, covering Boston and its closest neighbors including Cambridge, Quincy and Newton, in the Northeast region.
What cities are in the 617 area code?
Cities in the 617 area code include Boston, Cambridge, Quincy, Newton, Somerville, Brookline, Watertown, Chelsea, Everett and Belmont.
What time zone is 617 in?
617 is in the Eastern Time zone.
What is the overlay for the 617 area code?
617 shares its territory with 857. Both codes (617, 857) serve the same area, so 10-digit dialing is required for every call.
When did the 617 area code start?
617 went into service on January 1, 1947 as one of the original 1947 North American area codes.
Do I have to dial 10 digits for 617?
Yes. Because 617 is an overlay area, you must dial the full 10-digit number (area code + 7 digits) for every call.
Is 617 a toll-free or premium code?
No. 617 is a standard geographic area code, so calling it costs the same as any local or long-distance call on your plan. Toll-free calls use 800, 888, 877, 866, 855, 844 or 833.