| # | Company | Employees |
|---|---|---|
| 1 |
State Streetstatestreet.com
Global financial leader providing comprehensive investment services, institutional asset management, multi-asset trading, and digital solutions to enhance portfolio performance and decision making. |
46,913 |
| 2 |
Liberty Mutual Insurancelibertymutualgroup.com
Global leader in property and casualty insurance dedicated to fostering career growth, social responsibility, sustainability, diversity, and innovative solutions for customers worldwide |
37,734 |
| 3 |
Massachusetts General Hospitalmassgeneral.org
Dedicated to providing top-notch healthcare in a compassionate environment through innovative research and education, improving health in diverse communities served |
20,001 |
| 4 |
Boston Children's Hospitalchildrenshospital.org
A leading pediatric medical center providing comprehensive healthcare services for children from birth to 21 years, with specialized clinical programs and renowned physicians |
17,496 |
| 5 |
Santander USsantanderus.com
Provides auto, retail, commercial, and investment banking services alongside wealth management for millions of customers across various US hubs and global markets. |
13,806 |
| 6 |
Beth Israel Deaconess Medical Centerbidmc.org
World-class teaching hospital in Boston, part of a health care system focused on expanding access to great care, advancing medicine through research and education |
12,125 |
| 7 |
Boston Medical Center (BMC)bmc.org
delivering equitable healthcare, conducting research, and collaborating with communities to improve health outcomes and access for all patients |
10,149 |
| 8 |
Dana-Farber Cancer Institutedana-farber.org
Providing expert, compassionate care to children and adults with cancer while advancing understanding, treatment, cure, and prevention. |
8,981 |
| 9 |
American Toweramericantower.com
Global provider of digital infrastructure supporting mobile and broadband networks, enabling connectivity, innovation, and bridging digital divides worldwide. |
6,111 |
| 10 |
Tufts Medical Centertuftsmedicine.org
Academic medical center offering exceptional care in New England, specializing in primary care, trauma, heart transplants, and various specialties Conducts medical research and education |
6,018 |
| 11 |
Veolia | North Americaveolianorthamerica.com
Provides resource management solutions including water decontamination, toxic waste handling, fossil fuel alternatives, wastewater reuse, and battery recycling for cities and industries. |
5,812 |
| 12 |
Blue Cross Blue Shield of Massachusettsbluecrossma.org
Provides health insurance coverage to over 3 million members, focusing on community wellness, inclusivity, and employee development in Massachusetts. |
4,070 |
| 13 | 4,065 | |
| 14 |
Eastern Bankeasternbank.com
Provides banking, wealth management, and investment solutions for consumers and businesses across eastern Massachusetts, New Hampshire, Rhode Island, and Connecticut. |
2,498 |
| 15 |
Spaulding Rehabilitation Hospitalspauldingrehab.org
A leading rehabilitation facility providing comprehensive treatment, part of a network with specialty hospitals, skilled nursing facilities, and outpatient centers in Eastern Massachusetts |
2,441 |
| 16 | 2,028 | |
| 17 |
Harvard Medical School and Massachusetts General Hospitalmassgeneral.org
A prestigious hospital affiliated with Harvard Medical School, offering clinical experience and clerkships while supporting a large research enterprise |
1,967 |
| 18 |
Massachusetts Eye and Earmasseyeandear.org
Specialty hospital providing excellent care for disorders of the eye, ear, nose, and throat, while also focusing on education and research |
1,514 |
| 19 |
Commonwealth Care Alliancecommonwealthcarealliance.org
Mission-driven healthcare organization providing integrated, person-centered care and innovative health plans for individuals with significant needs in Massachusetts. |
1,503 |
| 20 |
Federal Reserve Bank of Bostonbostonfed.org
A leader in financial regulation and monetary policy, pioneering new payment strategies and using cutting-edge technology to ensure economic growth and stability |
1,324 |
| 21 |
Santander USsantanderus.com
Diversified financial business providing retail banking, commercial loans, consumer finance, private wealth management, and investment banking services across the United States for millions. |
1,040 |
| 22 |
Brigham and Women鈥檚 Faulkner Hospitalbrighamandwomensfaulkner.org
A 171-bed non-profit community teaching hospital offering comprehensive care in various specialties, nationally recognized for best practices in patient care and safety |
946 |
| 23 |
Berkshire Bankberkshirebank.com
A relationship-driven bank providing financial expertise in New England and New York, offering tailored banking solutions through various divisions |
936 |
| 24 |
New England Baptist Hospitalnebh.org
A leading regional provider of orthopedic surgery and musculoskeletal treatment, recognized for high patient satisfaction and clinical outcomes Collaborates with prestigious medical schools |
903 |
| 25 |
Massachusetts Port Authoritymassport.com
The company is focused on connecting Massachusetts and New England to the world through safe and efficient transportation, while also prioritizing diversity, sustainability, and community engagement |
758 |
| 26 |
Keolis SAkeolisna.com
Leading provider of passenger transportation services in the US and Canada, offering train, bus, and ADA paratransit services through public contracts |
731 |
| 27 |
Massachusetts Executive Office of Health and Human Servicesmass.gov
A health and human services organization in Massachusetts, working to promote health, resilience, and independence for residents through various programs |
707 |
| 28 |
Keolis Commuter Serviceskeolisna.com
Global leader in public transport operations, management, and innovation, providing transit solutions across various modes, including commuter rail networks |
668 |
| 29 |
Joslin Diabetes Centerjoslin.org
A world-renowned diabetes center dedicated to finding a cure and improving treatment for diabetes, with a mission to prevent, treat, and cure diabetes |
600 |
| 30 |
Nexampnexamp.com
A leading company in the new energy economy, specializing in deploying and operating solar energy assets for a cleaner, more secure energy future |
592 |
| 31 |
Vicinity Energyvicinityenergy.us
A clean energy company owning and operating district energy systems nationwide, providing reliable clean steam, hot water, chilled water, with a commitment to net zero carbon |
302 |
| 32 |
Starry, Inc.starry.com
This company offers lightning-fast internet service that is simple, innovative, and focused on making customers' internet experiences happier They are hiring diverse talent |
238 |
| 33 |
Advanced Poweradvancedpower.ch
A privately-owned company developing, owning, and managing power generation projects in Europe and North America with a focus on cleaner energy and reducing global emissions |
150 |
| 34 |
Kearsarge Energykearsargeenergy.com
A vertically integrated renewable energy project development and finance company that owns and operates solar and energy storage projects in the US |
28 |
| 35 |
Greenvolt Power NAgreenvolt.com
An international wind & solar developer in North America, producing renewable electricity with experienced employees and a passionate management team |
11 |
| 36 |
NSTAR Electric Constar.com
An electric utility serving residential, commercial, and industrial customers in parts of Massachusetts, Connecticut, New Hampshire, and western Massachusetts |
8 |
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How this list is built
Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Oct 24, 2026.
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