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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).

馃嚭馃嚫 Massachusetts29 companiesUpdated Nov 15, 2026

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.

#CompanyIndustryHeadquarters EmployeesFounded
1
athenahealthathenahealth.com

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 馃嚭馃嚫 Boston 8,956 1997
2
Rocket Softwarerocketsoftware.com

Partner for organizations transforming IT infrastructure, applications, and data from core systems to cloud with global support and innovation.

IT Services and IT Consulting 馃嚭馃嚫 Waltham 4,385 n/a
3
Curium Pharmacuriumpharma.com

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 馃嚭馃嚫 Boston 2,236 2017
4
Duck Creek Technologiesduckcreek.com

Provides cloud-based software solutions for property, casualty, and general insurance industries enabling agile, intelligent, and transparent insurance operations.

Software Development 馃嚭馃嚫 Boston 1,904 2000
5
Sovossovos.com

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 馃嚭馃嚫 Wilmington 1,861 2015
6
Black Duckblackduck.com

Provides comprehensive software security solutions that manage risks, ensure compliance, and enable innovation for regulated, AI-driven environments.

Software Development 馃嚭馃嚫 Burlington 1,295 2024
7
CFGIcfgi.com

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 馃嚭馃嚫 Boston 1,109 2000
8
SMYK Groupsmykgroup.com

A renowned brand offering children's products in Poland, with stores and an online shop, focused on customer satisfaction and product quality

Retail 馃嚭馃嚫 Warsaw 1,090 2000
9
Centerlinecenterlinecommunications.com

Designs, builds, and maintains wireless, wireline networks, and infrastructure facilities for Fortune 500 clients across the US Owned by Audax Private Equity

Telecommunications 馃嚭馃嚫 West Bridgewater 959 2006
10
Power Factorspowerfactors.com

Unified renewable energy operations with hardware, software, and services, managing extensive wind, solar, and storage assets globally for optimized performance.

Software Development 馃嚭馃嚫 Waltham 632 2013
11
Salsifysalsify.com

Salsify's Product Experience Management platform helps brand manufacturers, distributors, and retailers succeed in digital commerce through PIM, Syndication, and Automation

Software Development 馃嚭馃嚫 Boston 583 2012
12
Chase Corporationchasecorp.com

A leading manufacturer of protective materials for high reliability applications, offering industrial coatings, tapes, adhesives, and sealants globally under trusted brand names

Chemical Manufacturing 馃嚭馃嚫 Westwood 481 1946
13
Bartlett Nuclearbartlettnuclear.com

A leading provider of radiation safety personnel to the US nuclear power industry, offering technical services, facilities maintenance, engineering, training, and environmental services

Utilities 馃嚭馃嚫 Plymouth 475 1979
14
Black Diamond Networksblackdiamondnet.com

The company deploys skilled consultants in regulated industries for quality, compliance, and innovation, emphasizing speed, precision, and dynamic solutions

Staffing and Recruiting 馃嚭馃嚫 Andover 473 1999

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15
AMAG Pharmaceuticalsamagpharma.com

Develops and delivers innovative medicines to address complex, underserved health conditions, and invests in clinical research to improve patient care.

Pharmaceutical Manufacturing 馃嚭馃嚫 Waltham 368 1981
16
Millstone Medicalmillstonemedical.com

Millstone Medical provides post-manufacturing and aftermarket services to medical device manufacturers, focusing on quality, compliance, and business success

Medical Equipment Manufacturing 馃嚭馃嚫 Fall River 364 2000
17
Biodeal Pharmaceuticals Limitedbiodealpharma.com

Contract Development Manufacturing Organization offering diverse pharmaceutical formulations including nasal sprays, injectables, solid orals, nutraceuticals, and dermocosmetics for global clients.

Pharmaceutical Manufacturing 馃嚭馃嚫 Noida 346 2005
18
bluebird biolinkedin.com

This company focuses on developing curative gene therapies for severe genetic diseases like sickle cell, thalassemia, and cerebral adrenoleukodystrophy

Biotechnology Research 馃嚭馃嚫 Somerville 316 1993
19
Keystone Partnerskeystonepartners.com

This company provides comprehensive career management services, including outplacement, leadership development, coaching, succession planning, and retirement planning for individuals and organizations

Human Resources Services 馃嚭馃嚫 Boston 240 1982
20
Corza Wound Closurecorza.com

A leading provider of advanced surgical products and technologies, offering high performance sutures, microsurgical knives, and OEM components worldwide

Medical Equipment Manufacturing 馃嚭馃嚫 Westwood 222 1999
21
Fiduciary Trust Companyfiduciary-trust.com

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 馃嚭馃嚫 Boston 199 1885
22
oneZero Financial Systemsonezero.com

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 馃嚭馃嚫 Somerville 189 2009
23
Lacerta Group, LLC.lacerta.com

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 馃嚭馃嚫 Mansfield 187 1993
24
Vanguard Renewablesvanguardrenewables.com

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 馃嚭馃嚫 Weston 181 2014
25
Engagewareengageware.com

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 馃嚭馃嚫 Tewksbury 114 2000
26
CKEditorckeditor.com

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 馃嚭馃嚫 Boston 90 2006
27
Momentum Enterprisesthemomentumenterprises.com

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 馃嚭馃嚫 Newton 37 2015
28
B&E Groupbegroupllc.com

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 馃嚭馃嚫 Southwick 35 1950
29
AlphaStruxurealphastruxure.com

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 馃嚭馃嚫 Somerville 26 2019

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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 Nov 15, 2026.

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