Companies in Massachusetts: 183,767 businesses, the biggest headquarters and the state's largest employers

This page is for anyone sizing up Massachusetts businesses: suppliers and sellers choosing where to focus, job seekers, analysts and buyers vetting a vendor. It gives the Census count by county and sector, the 15 biggest headquarters with figures from their annual reports, the employer lists the Commonwealth and the City of Cambridge publish, and how to check a company before you deal with it.

How many businesses are in Massachusetts

In bands, 155,296 establishments have 1 to 19 employees (84.5%), 23,216 have 20 to 99 and 5,255 have 100 or more. These are County Business Patterns figures from the Census Bureau, covering all sectors (NAICS total). They count each location with a payroll separately, so a hospital system or retailer with 40 sites counts 40 times, and they leave out the self-employed. Employment is for the pay period including March 12, 2023.

Where they are

Average pay is our calculation from each county's payroll. Suffolk has the biggest workplaces in the state, 32.7 employees per establishment, because Boston's hospitals and financial firms sit there; Barnstable has 8.6, a county of shops, restaurants and contractors. Worcester County has nearly as many establishments as Essex but pays $4,400 a year less on average.

What Massachusetts businesses do

Health care employs more people than any other sector, and 76 hospital establishments alone employ 181,308. The research and development line is the one that sets Massachusetts apart: 1,825 labs averaging 55 employees each, with 1,190 of them in Middlesex County.

The biggest companies headquartered in Massachusetts

Ranked by revenue in each company's latest 10-K, with the city from the principal executive office on its cover page:

State Street's figure is total revenue (fee revenue plus net interest income). DraftKings ($6.05 billion), Clean Harbors of Norwell ($6.03 billion) and Veralto of Waltham ($5.50 billion) come next. Only five of the 15 are in the city of Boston; the rest line the Route 128 and I-495 belts, plus Eversource in Springfield and Hanover in Worcester. Farther out, Acushnet, the golf equipment maker, reported $2.56 billion from Fairhaven.

Some names you may expect aren't here. GE Aerospace's 10-K gives Evendale, Ohio as its principal executive office, Iron Mountain's gives Portsmouth, New Hampshire, and Keurig Dr Pepper's gives Frisco, Texas. Hologic of Marlborough was acquired and delisted in April 2026, and Global Partners of Waltham was delisted in July 2026. For the metro ranking to 30 names, see the largest companies in Boston.

Who employs the most people

The Commonwealth's annual financial report for fiscal 2025 lists the 20 largest private-sector employers, from June 2025 unemployment insurance reports compiled by the Executive Office of Labor and Workforce Development. It lists them alphabetically, without headcounts:

The report notes that Amazon, CVS Pharmacy, Home Depot, Target, UPS and Walmart are also large Massachusetts employers but are headquartered elsewhere. Only TJX and State Street appear on both the revenue table and the headcount list.

Cambridge publishes its own count every year, of employees working in the city:

Biogen (1,659), Alnylam (1,487), HubSpot (1,355) and Moderna (1,141) are also in the city's top 25. The figures are full-time equivalents collected in August and September 2025.

How to look up and vet a Massachusetts company

To vet a supplier, confirm the entity is active with the Corporations Division, check any professional license with the relevant state board, and for public companies read the 10-K's risk factors and legal proceedings sections before you sign.

Prospecting Massachusetts companies

The state rewards narrow targeting. A seller who treats Massachusetts as one market ends up chasing hospitals, labs and contractors with the same message; a seller who picks one county and one industry can count the whole market.

Illustrative example. The company, rates and results are fictional; the counts are from County Business Patterns.

Charles River Cold Chain (crcoldchain.example) maintains ultra-low freezers and monitors sample storage for biotech labs, and wants labs big enough to run their own vivarium or freezer farm.

1. Biotechnology R&D establishments (NAICS 541714) in Middlesex County with 20 to 249 employees: 91 + 52 + 42 = 185.
2. Suffolk County (Boston's Seaport and Longwood) adds 23 + 22 + 8 = 53, for 238 sites.
3. It drops the 1,000-plus sites, which buy service through corporate facilities contracts, and assumes half the rest store samples on site: about 120 labs.
4. At one in ten signing a service contract in year one, that's 12 accounts.

It targets lab operations managers and directors of research operations, not procurement, and times outreach to lab moves, expansions and new freezer purchases. Working out which of 238 sites store samples on site, and who runs lab operations there, is the research Bebop does for each account.

Subject: Freezer uptime at [Company]'s [street] lab

Hi [first name],

When a -80 fails at a lab your size, the cost is rarely the freezer: it's the samples and the weeks of work in it.

We service and monitor ultra-low freezers for Cambridge and Boston labs, with a four-hour on-site response and alarms that reach your team before the temperature drifts. Could I send what a service plan would cost for [number] units at [street]?

[Your name], Charles River Cold Chain

Next step: compare the metro picture in companies in Boston.