# 29 leading private equity-backed companies in Massachusetts

Tamtam tracks 29 private equity-backed companies headquartered in Massachusetts. This list ranks all of them by number of employees on LinkedIn, led by athenahealth, Rocket Software and Curium Pharma. Their median headcount is 368. Half of them were founded in 2000 or later. The most common headquarters are Boston (8), Somerville (3) and Waltham (3).

This selection of private equity-backed companies in Massachusetts includes large firms, mainly in IT services and software development. athenahealth, with 8956 employees, simplifies healthcare with technology. Rocket Software assists organizations in transforming IT infrastructure. Curium Pharma, founded in 2017, is a global leader in nuclear medicine, while Duck Creek Technologies provides cloud-based software for the insurance industry.

The companies listed show a concentration in the Boston metropolitan area, with many headquartered in Boston, Waltham, or Wilmington. The prevalence of IT services and software development, alongside pharmaceutical manufacturing, indicates a strong focus on technology and healthcare sectors within this group.

🇺🇸 Massachusetts · 29 companies · Updated Nov 15, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [athenahealth](https://www.tamtam.ai/c/athenahealth) (athenahealth.com)<br>The company strives to simplify healthcare with innovative technology for electronic health records, revenue cycle management, and patient engagement solutions | IT Services and IT Consulting | 🇺🇸 Boston | 8,956 | 1997 |
| 2 | [Rocket Software](https://www.tamtam.ai/c/rocket-software) (rocketsoftware.com)<br>Partner for organizations transforming IT infrastructure, applications, and data from core systems to cloud with global support and innovation. | IT Services and IT Consulting | 🇺🇸 Waltham | 4,385 |  |
| 3 | [Curium Pharma](https://www.tamtam.ai/c/curium-pharma) (curiumpharma.com)<br>Global leader in nuclear medicine, providing life-changing diagnostics and treatment for cancer patients worldwide through innovative radiopharmaceutical products and AI-driven solutions | Pharmaceutical Manufacturing | 🇺🇸 Boston | 2,236 | 2017 |
| 4 | [Duck Creek Technologies](https://www.tamtam.ai/c/duck-creek-technologies) (duckcreek.com)<br>Provides cloud-based software solutions for property, casualty, and general insurance industries enabling agile, intelligent, and transparent insurance operations. | Software Development | 🇺🇸 Boston | 1,904 | 2000 |
| 5 | [Sovos](https://www.tamtam.ai/c/sovos) (sovos.com)<br>Sovos provides scalable, secure, and user-friendly IT solutions for businesses to navigate global compliance regulations, serving Fortune 500 companies and organizations worldwide | Software Development | 🇺🇸 Wilmington | 1,861 | 2015 |
| 6 | [Black Duck](https://www.tamtam.ai/c/black-duck) (blackduck.com)<br>Provides comprehensive software security solutions that manage risks, ensure compliance, and enable innovation for regulated, AI-driven environments. | Software Development | 🇺🇸 Burlington | 1,295 | 2024 |
| 7 | [CFGI](https://www.tamtam.ai/c/cfgi) (cfgi.com)<br>Global accounting firm providing technical accounting, capital markets, tax, ESG, and transaction advisory services through former Big 4 professionals without auditor independence restrictions. | Business Consulting and Services | 🇺🇸 Boston | 1,109 | 2000 |
| 8 | [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 |
| 9 | [Centerline](https://www.tamtam.ai/c/centerline) (centerlinecommunications.com)<br>Designs, builds, and maintains wireless, wireline networks, and infrastructure facilities for Fortune 500 clients across the US Owned by Audax Private Equity | Telecommunications | 🇺🇸 West Bridgewater | 959 | 2006 |
| 10 | [Power Factors](https://www.tamtam.ai/c/power-factors) (powerfactors.com)<br>Unified renewable energy operations with hardware, software, and services, managing extensive wind, solar, and storage assets globally for optimized performance. | Software Development | 🇺🇸 Waltham | 632 | 2013 |
| 11 | [Salsify](https://www.tamtam.ai/c/salsify) (salsify.com)<br>Salsify's Product Experience Management platform helps brand manufacturers, distributors, and retailers succeed in digital commerce through PIM, Syndication, and Automation | Software Development | 🇺🇸 Boston | 583 | 2012 |
| 12 | [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 |
| 13 | [Bartlett Nuclear](https://www.tamtam.ai/c/bartlett-nuclear) (bartlettnuclear.com)<br>A leading provider of radiation safety personnel to the US nuclear power industry, offering technical services, facilities maintenance, engineering, training, and environmental services | Utilities | 🇺🇸 Plymouth | 475 | 1979 |
| 14 | [Black Diamond Networks](https://www.tamtam.ai/c/black-diamond-networks) (blackdiamondnet.com)<br>The company deploys skilled consultants in regulated industries for quality, compliance, and innovation, emphasizing speed, precision, and dynamic solutions | Staffing and Recruiting | 🇺🇸 Andover | 473 | 1999 |
| 15 | [AMAG Pharmaceuticals](https://www.tamtam.ai/c/amag-pharmaceuticals) (amagpharma.com)<br>Develops and delivers innovative medicines to address complex, underserved health conditions, and invests in clinical research to improve patient care. | Pharmaceutical Manufacturing | 🇺🇸 Waltham | 368 | 1981 |
| 16 | [Millstone Medical](https://www.tamtam.ai/c/millstone-medical) (millstonemedical.com)<br>Millstone Medical provides post-manufacturing and aftermarket services to medical device manufacturers, focusing on quality, compliance, and business success | Medical Equipment Manufacturing | 🇺🇸 Fall River | 364 | 2000 |
| 17 | [Biodeal Pharmaceuticals Limited](https://www.tamtam.ai/c/biodeal-pharmaceuticals-limited) (biodealpharma.com)<br>Contract Development Manufacturing Organization offering diverse pharmaceutical formulations including nasal sprays, injectables, solid orals, nutraceuticals, and dermocosmetics for global clients. | Pharmaceutical Manufacturing | 🇺🇸 Noida | 346 | 2005 |
| 18 | [bluebird bio](https://www.tamtam.ai/c/bluebird-bio) (linkedin.com)<br>This company focuses on developing curative gene therapies for severe genetic diseases like sickle cell, thalassemia, and cerebral adrenoleukodystrophy | Biotechnology Research | 🇺🇸 Somerville | 316 | 1993 |
| 19 | [Keystone Partners](https://www.tamtam.ai/c/keystone-partners) (keystonepartners.com)<br>This company provides comprehensive career management services, including outplacement, leadership development, coaching, succession planning, and retirement planning for individuals and organizations | Human Resources Services | 🇺🇸 Boston | 240 | 1982 |
| 20 | [Corza Wound Closure](https://www.tamtam.ai/c/corza-wound-closure) (corza.com)<br>A leading provider of advanced surgical products and technologies, offering high performance sutures, microsurgical knives, and OEM components worldwide | Medical Equipment Manufacturing | 🇺🇸 Westwood | 222 | 1999 |
| 21 | [Fiduciary Trust Company](https://www.tamtam.ai/c/fiduciary-trust-company) (fiduciary-trust.com)<br>Private wealth management firm offering objective advice and services for families, individuals, nonprofits, financial advisors, and single-family offices Specializes in wealth planning and investment management | Financial Services | 🇺🇸 Boston | 199 | 1885 |
| 22 | [oneZero Financial Systems](https://www.tamtam.ai/c/onezero-financial-systems) (onezero.com)<br>Technology company developing trading solutions for financial institutions globally with high reliability, scalability, and performance, handling billions in transactions daily | IT Services and IT Consulting | 🇺🇸 Somerville | 189 | 2009 |
| 23 | [Lacerta Group, LLC.](https://www.tamtam.ai/c/lacerta-group-llc) (lacerta.com)<br>A leading provider of thermoformed packaging solutions offering PET and sustainable packaging with in-house design capabilities and commitment to quality and sustainability | Packaging and Containers Manufacturing | 🇺🇸 Mansfield | 187 | 1993 |
| 24 | [Vanguard Renewables](https://www.tamtam.ai/c/vanguard-renewables) (vanguardrenewables.com)<br>A national leader in food waste recycling, Vanguard Renewables develops organic waste-to-energy projects to reduce greenhouse gas emissions and support regenerative agriculture | Environmental Services | 🇺🇸 Weston | 181 | 2014 |
| 25 | [Engageware](https://www.tamtam.ai/c/engageware) (engageware.com)<br>Provider of customer engagement solutions powered by AI to automate responses, improve customer experience, reduce call center workload, and drive growth for businesses | Software Development | 🇺🇸 Tewksbury | 114 | 2000 |
| 26 | [CKEditor](https://www.tamtam.ai/c/ckeditor) (ckeditor.com)<br>A leading creator of rich text editing software offering customizable and collaborative solutions for developers worldwide, with a strong focus on employee satisfaction | Software Development | 🇺🇸 Boston | 90 | 2006 |
| 27 | [Momentum Enterprises](https://www.tamtam.ai/c/momentum-enterprises) (themomentumenterprises.com)<br>An asset management company focused on community, family, and children, operating 17 businesses in New England, specializing in turning underperforming organizations into top-tier businesses | Investment Management | 🇺🇸 Newton | 37 | 2015 |
| 28 | [B&E Group](https://www.tamtam.ai/c/b-and-e-group) (begroupllc.com)<br>A company specializing in manufacturing machined components for aerospace, military, and space applications, as well as repairing commercial aerospace engine components | Aviation and Aerospace Component Manufacturing | 🇺🇸 Southwick | 35 | 1950 |
| 29 | [AlphaStruxure](https://www.tamtam.ai/c/alphastruxure) (alphastruxure.com)<br>Energy as a Service provider specializing in designing, building, owning, and operating customized energy infrastructure, including microgrids, with a focus on sustainability and cost stability | Renewables & Environment | 🇺🇸 Somerville | 26 | 2019 |

## 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 15, 2026.

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## The same list elsewhere in United States

- [Private equity-backed companies in the United States](https://www.tamtam.ai/l/private-equity-backed-companies-united-states) (579)
- [Private equity-backed companies in Texas](https://www.tamtam.ai/l/private-equity-backed-companies-texas) (75)
- [Private equity-backed companies in California](https://www.tamtam.ai/l/private-equity-backed-companies-california) (72)
- [Private equity-backed companies in New York State](https://www.tamtam.ai/l/private-equity-backed-companies-new-york-state) (45)
- [Private equity-backed companies in Florida](https://www.tamtam.ai/l/private-equity-backed-companies-florida) (44)
- [Private equity-backed companies in Illinois](https://www.tamtam.ai/l/private-equity-backed-companies-illinois) (33)
- [Private equity-backed companies in North Carolina](https://www.tamtam.ai/l/private-equity-backed-companies-north-carolina) (25)
- [Private equity-backed companies in New York](https://www.tamtam.ai/l/private-equity-backed-companies-new-york) (39)

## The same list elsewhere

- [Private equity-backed companies in the world](https://www.tamtam.ai/l/private-equity-backed-companies-in-the-world) (1,497)

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Source: https://www.tamtam.ai/l/private-equity-backed-companies-massachusetts