Company lists · Data refreshed September 2026

Top 25 Middle market private equity companies based in Boston, United States

Name: Middle market private equity companies based in Boston, United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 14, 2026 185 companies tracked

RevenueBase identified 185 middle market private equity companies headquartered in Boston, United States as of September 2026 and tracks 9,195 professional contacts across them, including 4,978 with verified work emails. Across the United States, New York is the largest hub for this category (911 companies); Boston has 185.

This list covers middle market private equity companies headquartered in Boston, United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 14, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 14, 2026 86% judged on-target in blind review

185Companies

9,195Contacts tracked

4,978Verified emails

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The 25 largest middle market private equity companies based in Boston, United States

Ranked by team size

Top 25 of 185 middle market private equity companies based in Boston, United States, ranked by team size, largest first. Data refreshed Sep 14, 2026. RevenueBase Smart Search rates how each company's information relates to middle market private equity companies: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Bain Capital	Partial evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	1,001-5,000	2,068 contacts →
	Partial evidence “Founded in 1984, Bain Capital is one of the world’s leading private investment firms.” Source: RevenueBase Database · checked Sep 14, 2026
2	Harbourvest Partners	Strong evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	1,001-5,000	1,353 contacts →
	Strong evidence “HarbourVest is an independent, global private markets firm with over 43 years of experience and $161 billion assets under management as of December 31, 2025.” Source: RevenueBase Database · checked Sep 14, 2026
3	Advent	Strong evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	501-1,000	1,025 contacts →
	Strong evidence “Advent is a leading global private equity investor committed to working in partnership with management teams, entrepreneurs, and founders to help transform businesses.” Source: RevenueBase Database · checked Sep 14, 2026
4	TA Associates	Strong evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	201-500	881 contacts →
	Strong evidence “TA is a leading global private equity firm focused on scaling growth in profitable companies.” Source: RevenueBase Database · checked Sep 14, 2026
5	PSG	Partial evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	51-200	513 contacts →
	Partial evidence “PSG is a growth equity firm that partners with software and technology-enabled services companies to help them navigate transformational growth, capitalize on strategic…” Source: RevenueBase Database · checked Sep 14, 2026
6	Summit Partners	Partial evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	51-200	465 contacts →
	Partial evidence “Summit Partners is a global alternative investment firm with capital dedicated to growth equity, fixed income, and public equity opportunities.” Source: RevenueBase Database · checked Sep 14, 2026
7	Berkshire Partners	Strong evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	201-500	255 contacts →
	Strong evidence “Berkshire Partners is a 100% employee-owned, multi-sector specialist investor in private and public equity, with a focus on North American-based, middle-market companies.” Source: RevenueBase Database · checked Sep 14, 2026
8	Charlesbank Capital Partners	Strong evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	51-200	236 contacts →
	Strong evidence “Based in Boston and New York City, Charlesbank is a leading middle-market private investment firm with $21.5 billion in assets under management as of 3/31/2026.” Source: RevenueBase Database · checked Sep 14, 2026
9	Audax Private Equity	Strong evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	201-500	211 contacts →
	Strong evidence “Headquartered in Boston, with offices in San Francisco, New York, London and Hong Kong, Audax Private Equity is a leading private equity platform focused on investing across the…” Source: RevenueBase Database · checked Sep 14, 2026
10	THL Partners	Strong evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	51-200	148 contacts →
	Strong evidence “THL Partners is a Boston-based private equity firm investing in middle-market growth companies in three industry groups: Financial Technology & Services, Healthcare, and…” Source: RevenueBase Database · checked Sep 14, 2026
11	Great Hill Partners	Strong evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	51-200	110 contacts →
	Strong evidence “Founded in 1998, Great Hill Partners is a private equity firm targeting investments of $100 million to $750 million in high-growth companies across the software, financial…” Source: RevenueBase Database · checked Sep 14, 2026
12	Spectrum Equity	Partial evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	51-200	94 contacts →
	Partial evidence “Founded in 1994, Spectrum Equity is a leading growth equity firm with offices in Boston, San Francisco, and London.” Source: RevenueBase Database · checked Sep 14, 2026
13	Highvista Strategies	Partial evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	51-200	91 contacts →
	Partial evidence “HighVista Strategies LLC is an employee-owned alternative asset manager that brings investors alpha opportunities in structurally inefficient markets.” Source: RevenueBase Database · checked Sep 14, 2026
14	BV Investment Partners	Strong evidence	Boston, United StatesHQ checked Sep 14, 2026	11-50	72 contacts →
	Strong evidence “BV Investment Partners is one of the oldest and most experienced sector-focused private equity firms in North America.” Source: RevenueBase Database · checked Sep 14, 2026
15	Parthenon Capital	Strong evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	11-50	68 contacts →
	Strong evidence “Parthenon Capital Partners (“Parthenon” or “Parthenon Capital”) is a private equity firm that partners with and invests in management teams and their companies.” Source: RevenueBase Database · checked Sep 14, 2026
16	Silversmith Capital Partners	Partial evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	51-200	63 contacts →
	Partial evidence “Founded in 2015, Silversmith Capital Partners is a Boston-based growth equity firm with over $5 billion in capital under management.” Source: RevenueBase Database · checked Sep 14, 2026
17	Volition Capital	Partial evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	11-50	63 contacts →
	Partial evidence “Volition Capital is a growth equity firm established in 2010 that focuses on investing in high-growth, founder-owned technology businesses across the U.S.” Source: RevenueBase Database · checked Sep 14, 2026
18	Baypine	Partial evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	11-50	61 contacts →
	Partial evidence “BayPine is a private investment firm that seeks to create lasting value for the firm's investors, portfolio companies and communities in which they operate by driving innovation…” Source: RevenueBase Database · checked Sep 14, 2026
19	Cove Hill Partners	Strong evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	51-200	53 contacts →
	Strong evidence “Cove Hill Partners is a private equity firm focused on partnering with outstanding management teams to build market-leading technology and consumer companies.” Source: RevenueBase Database · checked Sep 14, 2026
20	Ampersand Capital Partners	Strong evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	11-50	45 contacts →
	Strong evidence “Founded in 1988, Ampersand is a middle-market private equity firm with $3 billion of assets under management dedicated to growth-oriented investments in the healthcare sector.” Source: RevenueBase Database · checked Sep 14, 2026
21	Copley Equity Partners LLC	Strong evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	11-50	42 contacts →
	Strong evidence “Copley Equity Partners is a private investment firm based in Boston, MA, and Denver, CO.” Source: RevenueBase Database · checked Sep 14, 2026
22	NEW Boston Fund	Strong evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	51-200	41 contacts →
	Strong evidence “Founded in 1993, New Boston is a real estate investment management firm based in Boston, MA that manages over 1.2 billion dollars in private equity capital on behalf of high net…” Source: RevenueBase Database · checked Sep 14, 2026
23	M33 Growth	Indirect evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	11-50	38 contacts →
	Indirect evidence “M33 Growth is a venture and growth stage investment firm that seeks to partner with founders and CEOs to rapidly scale their companies and break through as industry leaders.” Source: RevenueBase Database · checked Sep 14, 2026
24	Solamere Capital, LLC	Strong evidence	Boston, United StatesHQ checked Sep 14, 2026	11-50	37 contacts →
	Strong evidence “Founded in 2008, Solamere is a multi-strategy private equity firm with offices in Boston and New York City.” Source: RevenueBase Database · checked Sep 14, 2026
25	Conjoin Group	Strong evidence	Boston, MA, United StatesHQ checked Sep 14, 2026	201-500	36 contacts →
	Strong evidence “The ConJoin Group aligns with Venture Capital and Private Equity firms by investing our own capital,$250M in committed funds, and delivering a suite of services designed to…” Source: RevenueBase Database · checked Sep 14, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: middle market private equity companies. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names middle market private equity companies.
Partial evidence: Its own public description names part of middle market private equity companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name middle market private equity companies. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 185 middle market private equity companies based in Boston, United States

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Middle market private equity companies based in Boston, United States at a glance

As of Sep 14, 2026

54.1%Verified-email coverage

49.7Average contacts per company

1-10Median size (employees)

Sep 14, 2026Page data refreshed

Companies by employee count

1-10

108

11-50

51-200

201-500

501-1,000

1,001-5,000

Email recency for this list is measured across the whole United States list rather than for Boston, so it is reported there. Company counts and contact totals on this page are exact for Boston, over 185 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among middle market private equity companies, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in Boston, United States whose own description of what they do matches “middle market private equity companies”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search: RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names middle market private equity companies), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude: Companies whose own description does not clearly place them among middle market private equity companies, and records with no verified work email. Companies headquartered outside Boston are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 4,978 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 14, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Middle market private equity companies by metro in the United States

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names middle market private equity companies, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many middle market private equity companies are there based in Boston, United States?

RevenueBase identified 185 middle market private equity companies headquartered in Boston, United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Bain Capital, headquartered in Boston, tops this list with the largest team on record.

Which city in the United States has the most middle market private equity companies?

New York leads the United States with 911 headquartered companies, followed by Chicago (317) and Dallas (276). Boston has 185.

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 4,978 verified decision-maker contacts tracked across these 185 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 14, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.