# List of corporate groups and holding companies in Massachusetts

Tamtam tracks 87 corporate groups and holding companies headquartered in Massachusetts. This list ranks the 50 largest by number of employees on LinkedIn, led by Mass General Brigham, Santander US and Clean Harbors. Their median headcount is 1,090. Half of them were founded in 1972 or later. The most common headquarters are Boston (13), Burlington (4) and Somerville (2).

The companies listed in Massachusetts are primarily large corporate groups in healthcare, financial services, and environmental services. Mass General Brigham is an integrated academic health system, and Santander US provides banking services. Clean Harbors specializes in hazardous waste management, while EG America is a convenience store retailer.

A notable pattern among these companies is the strong presence of the healthcare sector, with several large hospitals and health systems like Partners HealthCare and Tufts Medical Center. Many of these entities are headquartered in Boston, indicating a geographical concentration of major corporate operations in the city.

🇺🇸 Massachusetts · 50 companies · Updated Nov 11, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Mass General Brigham](https://www.tamtam.ai/c/mass-general-brigham) (massgeneralbrigham.org)<br>Integrated academic health system providing patient care, research, teaching, and community services through hospitals, insurance, and specialized medical centers. | Hospitals and Health Care | 🇺🇸 Somerville | 17,890 |  |
| 2 | [Santander US](https://www.tamtam.ai/c/santander-us-boston) (santanderus.com)<br>Provides auto, retail, commercial, and investment banking services alongside wealth management for millions of customers across various US hubs and global markets. | Financial Services | 🇺🇸 Boston | 13,806 | 1857 |
| 3 | [Clean Harbors](https://www.tamtam.ai/c/clean-harbors) (cleanharbors.com)<br>Provider of hazardous waste management, emergency spill response, industrial cleaning, recycling, and used oil re-refining services across North America. | Environmental Services | 🇺🇸 Norwell | 13,449 | 1980 |
| 4 | [EG America](https://www.tamtam.ai/c/eg-america) (eg-america.com)<br>A rapidly growing convenience store retailer in the US, part of a global company, offering top-notch products and services nationwide | Retail | 🇺🇸 Westborough | 9,343 | 2019 |
| 5 | [Partners HealthCare](https://www.tamtam.ai/c/partners-healthcare) (partners.org)<br>Integrated healthcare system offering coordinated care, high-quality services, research, teaching, and community outreach through academic medical centers and various healthcare entities | Hospitals and Health Care | 🇺🇸 Somerville | 6,751 | 1994 |
| 6 | [Teradyne](https://www.tamtam.ai/c/teradyne) (teradyne.com)<br>This company provides advanced test solutions for semiconductors, electronic systems, wireless devices, and robotics to improve productivity and lower costs for manufacturers worldwide | Semiconductor Manufacturing | 🇺🇸 North Reading | 6,210 | 1960 |
| 7 | [American Tower](https://www.tamtam.ai/c/american-tower) (americantower.com)<br>Global provider of digital infrastructure supporting mobile and broadband networks, enabling connectivity, innovation, and bridging digital divides worldwide. | Telecommunications | 🇺🇸 Boston | 6,111 | 1995 |
| 8 | [Tufts Medical Center](https://www.tamtam.ai/c/tufts-medical-center) (tuftsmedicine.org)<br>Academic medical center offering exceptional care in New England, specializing in primary care, trauma, heart transplants, and various specialties Conducts medical research and education | Hospitals and Health Care | 🇺🇸 Boston | 6,018 | 1796 |
| 9 | [Tripadvisor](https://www.tamtam.ai/c/tripadvisor) (tripadvisor.com)<br>A leading travel guidance platform with 1 billion reviews, offering deals on accommodations, experiences, and restaurants to help travelers plan their trips | Software Development | 🇺🇸 Needham | 5,762 |  |
| 10 | [Kaleida Health](https://www.tamtam.ai/c/kaleida-health) (kaleidahealth.org)<br>Leading healthcare provider in Western New York offering state-of-the-art technology, comprehensive services, and compassionate care to over one million patients annually | Hospitals and Health Care | 🇺🇸 Burlington | 5,060 |  |
| 11 | [Progress Software](https://www.tamtam.ai/c/progress-software) (progress.com)<br>Helping businesses drive innovation and success with high-impact application products, deployment flexibility, and secure management solutions, trusted by enterprises and developers worldwide | Software Development | 🇺🇸 Burlington | 4,212 | 1981 |
| 12 | [The Kraft Group & Affiliates](https://www.tamtam.ai/c/the-kraft-group-and-affiliates) (thekraftgroup.com)<br>Holding company with diverse interests in paper manufacturing, sports, real estate, private equity, and philanthropy across global markets. | Spectator Sports | 🇺🇸 Foxboro | 2,643 | 1965 |
| 13 | [Acushnet Company](https://www.tamtam.ai/c/acushnet-company) (employment.acushnetgolf.com)<br>Leading golf company offering high-quality golf equipment, apparel, and accessories for serious and recreational golfers worldwide. | Manufacturing | 🇺🇸 Fairhaven | 2,611 |  |
| 14 | [argenx](https://www.tamtam.ai/c/argenx) (argenx.com)<br>Global immunology company focused on developing novel antibody-based medicines for severe autoimmune diseases through collaborations with leading researchers | Biotechnology Research | 🇺🇸 Boston | 2,315 | 2008 |
| 15 | [The Boston Beer Company](https://www.tamtam.ai/c/the-boston-beer-company) (bostonbeer.com)<br>A passionate beer company with 40 years of brewing experience, focused on cultivating talent and pushing boundaries while having fun | Food and Beverage Services | 🇺🇸 Boston | 2,262 | 1984 |
| 16 | [Werfen North America](https://www.tamtam.ai/c/werfen-north-america) (werfen.com)<br>Worldwide leader specialized diagnostics: hemostasis, acute care, transfusion, autoimmunity, transplant. Operates in over 100 territories, with headquarters in Barcelona, Spain, and technology centers in the US and Europe. | Medical Equipment Manufacturing | 🇺🇸 Bedford | 1,933 | 1959 |
| 17 | [WinnCompanies](https://www.tamtam.ai/c/winncompanies) (winncompanies.com)<br>A leader in property development and management, creating homes and communities through teamwork, innovation, and a commitment to enhancing lives | Real Estate | 🇺🇸 Boston | 1,880 | 1971 |
| 18 | [Solid Security Sp. z o.o.](https://www.tamtam.ai/c/solid-security-sp-z-o-o) (solidsecurity.pl)<br>A Polish-owned security company offering a wide range of protection services, including on-site security, alarm systems, CCTV installation, vehicle monitoring, and cash processing | Security and Investigations | 🇺🇸 Warsaw | 1,765 | 1991 |
| 19 | [Motion Recruitment Partners LLC](https://www.tamtam.ai/c/motion-recruitment-partners-llc) (motionrp.com)<br>Global talent solutions provider offering IT staffing, consulting, telecom talent solutions, RPO/MSP services, and government IT subcontracting through its various sub-brands | Staffing and Recruiting | 🇺🇸 Boston | 1,639 | 1989 |
| 20 | [Vetcor](https://www.tamtam.ai/c/vetcor) (vetcor.com)<br>A national network of 800+ veterinary hospitals offering tailored support, mentorship, competitive salaries, and generous benefits to help veterinary professionals thrive | Veterinary Services | 🇺🇸 Norwell | 1,475 | 1997 |
| 21 | [Seven Hills Foundation](https://www.tamtam.ai/c/seven-hills-foundation) (sevenhills.org)<br>Provide support and services to individuals with disabilities and life challenges across Massachusetts and Rhode Island through extensive programming. | Individual and Family Services | 🇺🇸 Worcester | 1,381 | 1951 |
| 22 | [Orbia](https://www.tamtam.ai/c/orbia) (orbia.com)<br>A global company tackling challenges in water and food security, information access, connectivity, and energy transition across various sectors | Utilities | 🇺🇸 Boston | 1,300 |  |
| 23 | [Tufts Medicine](https://www.tamtam.ai/c/tufts-medicine) (tuftsmedicine.org)<br>A health system in Massachusetts that brings together providers to offer high-quality, cost-effective care, from serious illnesses to chronic conditions, throughout the region | Hospitals and Health Care | 🇺🇸 Burlington | 1,241 | 2014 |
| 24 | [Boston Globe Media](https://www.tamtam.ai/c/boston-globe-media) (bostonglobemedia.com)<br>Largest New England news organization providing trusted journalism, engaging content marketing, and targeted advertising to influential audiences. | Online Audio and Video Media | 🇺🇸 Boston | 1,240 | 1872 |
| 25 | [SMYK Group](https://www.tamtam.ai/c/smyk-group) (smykgroup.com)<br>A renowned brand offering children's products in Poland, with stores and an online shop, focused on customer satisfaction and product quality | Retail | 🇺🇸 Warsaw | 1,090 | 2000 |
| 26 | [Papa Gino's](https://www.tamtam.ai/c/papa-gino-s) (papaginos.com)<br>A Massachusetts-based company operating over 370 Papa Gino's and D'Angelo restaurants in New England, specializing in pizza, grilled sandwiches, and dual-concept dining | Restaurants | 🇺🇸 Dedham | 1,005 | 1961 |
| 27 | [NSTAR, now Eversource Energy- Follow our new company page, Eversource Energy](https://www.tamtam.ai/c/nstar-now-eversource-energy-follow-our-new-company-page-eversource-energy) (eversource.com)<br>A united energy company formed through a merger, focused on delivering reliable energy and superior customer service in New England | Utilities | 🇺🇸 Westwood | 923 |  |
| 28 | [Care Access](https://www.tamtam.ai/c/care-access) (careaccess.com)<br>Global research site facilitating access to clinical research to increase availability of new treatments in communities worldwide | Research Services | 🇺🇸 Boston | 860 | 2015 |
| 29 | [Gradiant](https://www.tamtam.ai/c/gradiant) (gradiant.com)<br>Provides advanced water and wastewater treatment solutions for critical industries, reducing water usage, reclaiming resources, and renewing wastewater into freshwater. | Environmental Services | 🇺🇸 Woburn | 859 | 2013 |
| 30 | [Jack Conway & Co., Inc.](https://www.tamtam.ai/c/jack-conway-and-co-inc) (jackconway.com)<br>A Massachusetts-based real estate company provides quality services across multiple locations, emphasizing family-like relationships, excellence, and global outreach | Real Estate | 🇺🇸 Hanover | 853 | 1956 |
| 31 | [Harvey Building Products Corporation](https://www.tamtam.ai/c/harvey-building-products-corporation) (harveybuildingproducts.com)<br>A privately owned manufacturing corporation specializing in premium windows and doors, serving customers along the East Coast to the Rockies | Wholesale Building Materials | 🇺🇸 Waltham | 822 | 1961 |
| 32 | [New England Biolabs](https://www.tamtam.ai/c/new-england-biolabs) (neb.com)<br>Leading enzyme producer for molecular biology, offering extensive recombinant and native enzymes for genomic research and related biotechnologies. | Biotechnology Research | 🇺🇸 Ipswich | 815 | 1974 |
| 33 | [Doble Engineering](https://www.tamtam.ai/c/doble-engineering) (doble.com)<br>Providing diagnostics and engineering expertise for the energy industry, specializing in condition monitoring, enterprise asset management, in-service testing, protection testing, security, and compliance solutions | Appliances, Electrical, and Electronics Manufacturing | 🇺🇸 Marlborough | 782 | 1920 |
| 34 | [BSC Group](https://www.tamtam.ai/c/bsc-group) (bscgroup.com)<br>Multidisciplinary consulting firm providing civil engineering, environmental services, surveying, transportation planning, landscape architecture, structural engineering, and custom software solutions | Civil Engineering | 🇺🇸 Boston | 737 | 1965 |
| 35 | [Keurig Green Mountain, Inc.](https://www.tamtam.ai/c/keurig-green-mountain-inc) (keurigdrpepper.com)<br>Leading North American beverage company with extensive portfolio including coffee, soft drinks, tea, water, juice, and mixers, strong distribution network. | Food and Beverage Services | 🇺🇸 Burlington | 701 | 2018 |
| 36 | [Buyers Edge Platform](https://www.tamtam.ai/c/buyers-edge-platform) (buyersedgeplatform.com)<br>Technology-driven platform enhancing foodservice supply chain efficiency, cost reduction, and automation through digital procurement, fresh solutions, and software. | Hospitality | 🇺🇸 Waltham | 606 | 2018 |
| 37 | [Coghlin Companies](https://www.tamtam.ai/c/coghlin-companies) (coghlincompanies.com)<br>Coghlin Companies offers Time to Market Services for commercializing industrial equipment and medical devices, including engineering, manufacturing, and global fulfillment | Manufacturing | 🇺🇸 Worcester | 593 | 1885 |
| 38 | [UFP Technologies](https://www.tamtam.ai/c/ufp-technologies) (ufpt.com)<br>Specializing in custom solutions for medical devices, sterile packaging, and other engineered products, serving as a crucial link in the medical device supply chain | Medical Equipment Manufacturing | 🇺🇸 Newburyport | 535 | 1963 |
| 39 | [SLC Management](https://www.tamtam.ai/c/slc-management) (slcmanagement.com)<br>SLC Management helps clients achieve long-term income and capital appreciation goals through disciplined investment management across fixed income, real estate, alternative credit, and infrastructure | Financial Services | 🇺🇸 Wellesley Hills | 534 | 2013 |
| 40 | [Trexon](https://www.tamtam.ai/c/trexon) (trexon.com)<br>Offers unique connectivity solutions. Withstands tough environments, exacting applications. Provides wide variety of high-performance wire and cable solutions through collective brand strength. | Appliances, Electrical, and Electronics Manufacturing | 🇺🇸 Boston | 525 |  |
| 41 | [Mestek, Inc.](https://www.tamtam.ai/c/mestek-inc) (mestek.com)<br>A diverse family of over 45 specialty manufacturers offering a wide range of HVAC products, coil handling equipment, metal forming machinery, and more | Manufacturing | 🇺🇸 Westfield | 524 | 1946 |
| 42 | [Stratus Technologies](https://www.tamtam.ai/c/stratus-technologies) (penguinsolutions.com)<br>Stratus provides Edge Computing solutions for businesses seeking predictable performance, minimal risk, and continuous availability of critical applications | Software Development | 🇺🇸 Maynard | 519 |  |
| 43 | [Advocates for Human Potential, Inc.](https://www.tamtam.ai/c/advocates-for-human-potential-inc) (ahpnet.com)<br>Providing practical solutions to improve health and human services systems through research, evaluation, training, and consulting for organizations serving vulnerable populations | Business Consulting and Services | 🇺🇸 Sudbury | 515 | 1986 |
| 44 | [New England Patriots](https://www.tamtam.ai/c/new-england-patriots) (patriots.com)<br>Professional football team based in New England with a rich history dating back to 1959, playing at Gillette Stadium in Foxborough, MA | Spectator Sports | 🇺🇸 Foxborough | 497 | 1960 |
| 45 | [Chase Corporation](https://www.tamtam.ai/c/chase-corporation) (chasecorp.com)<br>A leading manufacturer of protective materials for high reliability applications, offering industrial coatings, tapes, adhesives, and sealants globally under trusted brand names | Chemical Manufacturing | 🇺🇸 Westwood | 481 | 1946 |
| 46 | [The Middlesex Corporation](https://www.tamtam.ai/c/the-middlesex-corporation) (middlesexco.com)<br>A leader in heavy civil construction and paving industries, prioritizing safety, quality, and excellence since 1972 Committed to growth and success | Construction | 🇺🇸 Littleton | 480 | 1972 |
| 47 | [Cold Chain Technologies](https://www.tamtam.ai/c/cold-chain-technologies) (coldchaintech.com)<br>Specializing in thermal packaging solutions for temperature-sensitive materials, with a focus on the life science industry, known for innovation and reliability | Pharmaceutical Manufacturing | 🇺🇸 Franklin | 478 | 1967 |
| 48 | [Veson Nautical](https://www.tamtam.ai/c/veson-nautical) (veson.com)<br>Provides software solutions for managing bulk marine freight, including contract management, vessel documentation, and data analytics for shipping. | Software Development | 🇺🇸 Boston | 475 |  |
| 49 | [Balise Motor Sales](https://www.tamtam.ai/c/balise-motor-sales) (baliseauto.com)<br>A major retailer in New England, specializing in new and used vehicle sales and related services with over 1,300 employees | Motor Vehicle Manufacturing | 🇺🇸 West Springfield | 440 | 1919 |
| 50 | [Vestmark](https://www.tamtam.ai/c/vestmark) (vestmark.com)<br>A leading provider of portfolio management solutions and outsourced services for financial institutions, enabling efficient management of client portfolios | Software Development | 🇺🇸 Wakefield | 437 | 2001 |

## 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 Nov 11, 2026.

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Source: https://www.tamtam.ai/l/holding-companies-massachusetts