What is the 857 Area Code? Time Zone and Location
- Area code 857 is located in Massachusetts and serves the Boston metropolitan area — it is an overlay for area code 617 and serves the same geographic area.
- Combined with overlay 617, it covers 36 cities across 3 counties in Greater Boston, serving a population of 3,155,919.
- Major cities covered include Boston, Cambridge, Quincy, Newton, Somerville, Brookline, Belmont, Chelsea, Charlestown, Everett, Waltham, Watertown, Milton, Malden, Hyde Park, Jamaica Plain, Dorchester, South Boston, Brighton, and Winthrop.
- The 857 area code is located in the Eastern Time Zone — following UTC−5 during Eastern Standard Time and UTC−4 during Eastern Daylight Time.
- Area code 857 was put into service on May 2, 2001, and was the 294th area code in service — one of 26 area codes introduced in 2001 — created to relieve the pressure on the 617 area code as numbers in 617 were being exhausted by Boston's growing tech and biotech economy.
- 10-digit dialing mandatory for all local calls within the 617/857 overlay complex.
Quick Facts
| Area Code | 857 |
|---|---|
| Country | United States |
| State / Region | Massachusetts (core Greater Boston — city of Boston and inner suburbs) |
| Area Code Type | Overlay area code (shares region with area code 617) |
| Overlay Codes | 617 |
| Major Cities Covered | Boston, Cambridge, Quincy, Newton, Somerville, Brookline, Belmont, Chelsea, Charlestown, Everett, Waltham, Watertown, Milton, Malden, Hyde Park, Jamaica Plain, Dorchester, South Boston, East Boston, Brighton, Winthrop |
| Primary City Association | Boston, Massachusetts (state capital) |
| Geographic Coverage | 36 cities across 3 counties in Greater Boston, including Suffolk, Middlesex, and Norfolk counties |
| Time Zone | Eastern Time Zone (ET) |
| Standard Time Offset | UTC −5 hours |
| Daylight Saving Time | UTC −4 hours (EDT) |
| DST Period (2026 Example) | March → November |
| Introduced / Activation Date | May 2, 2001 |
| Reason for Creation | Created as an overlay to the 617 area code in 2001, as Boston's rapidly growing technology, biomedical, and financial sectors drove explosive demand for new phone numbers that exhausted the available supply in 617 |
| Dialing Requirement | 10-digit dialing mandatory (due to 617/857 overlay complex) |
| Coverage Nature | Overlay complex — 857 and 617 share the same Greater Boston geography |
| Population Coverage | Combined with overlay 617, serves a population of 3,155,919 across the Greater Boston metro |
| Nearby / Related Area Codes | 339/781 (Boston suburbs), 351/978 (Lowell/Lawrence), 413 (Springfield), 508/774 (Worcester/Cape Cod), 617 (857's parent overlay), 401 (Providence, RI), 603 (New Hampshire) |
| Telecom System | North American Numbering Plan (NANP) |
| Major Carriers | Verizon Wireless holds 17% of active prefixes, followed by Omnipoint/T-Mobile (16%), Onvoy (11%), Metro by T-Mobile (7%), and Paetec Itel (5%) |
| Example Phone Format | (857) XXX-XXXX |
| Usage Type | Mobile, landline, VoIP numbers |
| Business Use | One of the most commercially valuable Boston-area codes — widely used by startups, research institutions, healthcare networks, and financial services firms across Greater Boston |
| Number Availability | Currently uses 359 telephone prefixes — approximately 33% wireless and 67% landline — with solid availability across the 617/857 overlay complex |
| Area Code Status | Active and widely used |
| Demographic Profile | The 857 area code encompasses a dynamic and growing population concentrated in Middlesex, Suffolk, and Norfolk counties — with a notably younger median age than the national average, high labor force participation, and a diverse, highly educated workforce reflecting Boston's academic and innovation economy |
| Economic Profile | The 857 region enjoys a median household income of approximately $110,390 and per capita income of approximately $71,409 — among the highest of any Boston-area code — driven by the concentration of biotech, pharmaceutical, financial services, and technology firms |
| Common Legitimate Callers | Mass General Brigham nurse lines, Fidelity investment advisors, Harvard and MIT alumni relations, and Vertex Pharmaceuticals recruiters are among the most recognized legitimate callers from 857 numbers |
Is the 857 Area Code a Scam?
| Spam Ranking | Ranked #220 for spam complaints nationally, accounting for approximately 0.18% of all spam complaints |
|---|---|
| Spam Growth | Spam calls in Massachusetts increased by 160.7% over the past year — one of the sharpest statewide increases in New England — with the highest volume recorded in January 2026 accounting for 14.71% of all calls |
| Most Common Complaint Type | Prerecorded voice complaints make up 48.69% of total reports — the dominant complaint type — followed by live voice at 42.41% and text message at 8.9% |
| Top Scam Categories | IRS calls make up 14.14% of complaints — the single largest category by a wide margin — followed by health insurance (9.95%), criminal charges (6.81%), solar panels (5.76%), and Medicare/Medicaid (3.66%) |
| Top Reported Cities for Complaints | West Roxbury, MA leads with 3.28% of complaints, followed by Quincy, MA (1.68%), Boston, MA (1.24%), Shrewsbury, MA (0.92%), and Groton, MA (0.72%) |
| Common Labels | IRS arrest threat, voicemail hijacker, fake debt collector, utility disconnection fraudster, pharmacy services scammer, Boston Police impersonator |
| Spoofing Risk | Scammers fake their caller ID to display local or familiar 857 numbers — if you live in or near Massachusetts (Boston, Cambridge, Quincy), scammers know you are more likely to answer what appears to be a local call |
| “Institutional Authority” Exploitation | The 857/617 corridor is uniquely vulnerable to institutional authority impersonation — home to Harvard, MIT, Mass General, Fidelity, and major government agencies, a Boston-area call from a “health plan,” “IRS office,” or “hospital billing department” carries exceptional credibility with local residents |
| Typical Strategy | Neighbor spoofing — appearing as a familiar Boston, Cambridge, or Quincy number, then leveraging Boston's institutional reputation to make government, healthcare, or legal impersonation threats more convincing |
| Signature Scam — IRS “Yes” Voice Recording Trap | Scammers call claiming to be from the IRS and ask yes/no questions such as “Can you hear me?”, “Are you the person responsible for paying the telephone bill?”, or “Are you the homeowner?” — if the victim answers “yes,” it is recorded and used to authorize bogus charges on a credit card or phone bill |
| Signature Scam — Boston Police Impersonation | A police imposter calls an unsuspecting victim and informs them there is a warrant out for their arrest unless they pay an amount owed on a loan or ticket — using the credibility of the Boston Police Department to frighten victims into immediate payment by gift card or wire transfer |
| Signature Scam — Voicemail & Call Forwarding Hijacking | Scammers gain access to residents' phones and secretly activate call forwarding without permission — victims in the Boston area stop receiving voicemails and discover their calls are being rerouted to a scammer's number, with phone bills showing calls forwarded to unknown numbers and friends reporting the mailbox is full when it is empty — using intercepted voicemails to gather personal information and business details |
| Signature Scam — Fake “CBE Group” Debt Collection | Callers claiming to be from “CBE Group” or “Dynamic Recovery” about a “personal business matter” refuse to state their company name or explain the supposed debt unless the victim first verifies their date of birth or Social Security number — a tactic to steal identity information rather than collect any legitimate debt |
| Shared 617/857 Scam Pattern — MassHealth & BCBS Impersonation | Both the 617 and 857 area codes face specific MassHealth and Blue Cross Blue Shield impersonation scams — callers knowing the victim's full name open with “What is your Social Security Number to verify your records?” and may offer an unsolicited in-home health assessment to capture Medicare numbers for fraudulent billing |
| Reporting Authority | Report suspicious calls to the FTC at ReportFraud.ftc.gov, to the Massachusetts AG at mass.gov/ago, or at 617-727-8400; for BCBS fraud, call their Fraud Hotline at 1-800-992-4100 |
| Key Risk Indicator | IRS calls opening with “Can you hear me?”, Boston Police warrant threats demanding immediate payment, voicemail suddenly going dead without explanation, debt collectors who refuse to identify themselves or mail validation, or MassHealth callers immediately asking for your SSN |
| Safety Tip | The IRS never calls to demand immediate payment or record your responses — all IRS contacts begin with an official letter through the U.S. Mail. Boston Police do not call to demand payment to avoid arrest. Any call that opens by trying to get you to say “yes” should be hung up on immediately |
What Are the Business Benefits of the 857 Area Code?
| Local Presence | An 857 number establishes immediate local credibility in one of America's premier innovation economies — Greater Boston, where biotech, pharmaceuticals, financial services, and world-class universities converge in the most research-intensive corridor on the East Coast |
|---|---|
| Customer Trust Factor | A local Boston 857 number dramatically increases answer rates vs. unknown out-of-state numbers in a sophisticated, highly educated market where institutional credibility and local identity are primary drivers of trust |
| Coverage Advantage | One number covers 36 cities across Suffolk, Middlesex, and Norfolk counties — reaching the full Boston core from Chelsea and East Boston through Cambridge and Somerville to Quincy and Newton |
| Innovation Ecosystem Access | Cambridge — within the 857 coverage area — is home to Harvard University and MIT, with Kendall Square described as “the most innovative square mile on the planet,” anchoring one of the world's most celebrated biotech and innovation clusters |
| VoIP Compatibility | Easily available for SaaS platforms, call centers, and remote teams serving the Greater Boston market |
| Scalability | Covers roughly 3.47 million unique phone numbers across the 617/857 overlay complex |
| Affluent & Educated Market | With a median household income of approximately $110,390 and per capita income of $71,409, the 857 region is one of the wealthiest and most highly educated suburban markets in the nation, particularly valuable for financial services, healthcare, and premium consumer businesses |
| Marketing Use | Ideal for local SEO, digital ads, and customer outreach across Boston, Cambridge, Quincy, Somerville, Newton, Brookline, Everett, Malden, Chelsea, Waltham, Watertown, and surrounding communities |
| Startup Friendly | Highly attractive for biotech, fintech, healthtech, and AI startups given Boston's extraordinary concentration of research universities, hospital systems, and venture capital — one of the top three startup ecosystems in the United States |
| Call Routing Flexibility | Can route calls globally while appearing local to Boston customers — particularly valuable for international life sciences and financial services companies using Boston as a US gateway city |
| Top Industries | Biotechnology and pharmaceutical (Moderna, Biogen, Vertex, Genzyme), financial services (Fidelity Investments, State Street, Liberty Mutual), higher education (Harvard, MIT, Boston University, Northeastern), healthcare (Mass General Brigham, Brigham and Women's, Dana-Farber), technology, legal services, and tourism (Freedom Trail, Fenway Park) benefit most from a local 857 presence |
| Use Case Examples | AI receptionist, biotech and pharma clinical support lines, financial advisory and wealth management services, university-affiliated research services, hospital and healthcare network lines, legal and professional services, technology startup hotlines, hospitality and tourism businesses, and local retail and restaurant services |
