Company lists · Data refreshed September 2026

Top 25 Middle market investment firms based in the United States

Name: Middle market investment firms based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 28, 2026 4,178 companies tracked

RevenueBase identified 4,178 middle market investment firms headquartered in the United States as of September 2026 and tracks 64,480 professional contacts across them, including 33,107 with verified work emails. New York is the largest hub.

This list covers middle market investment firms headquartered in the 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 28, 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 28, 2026 86% judged on-target in blind review

4,178Companies

64,480Contacts tracked

33,107Verified emails

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The 25 largest middle market investment firms based in the United States

Ranked by team size

Top 25 of 4,178 middle market investment firms based in the United States, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to middle market investment firms: 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	The Carlyle Group	Partial evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	1,001-5,000	2,515 contacts →
	Partial evidence “Carlyle (NASDAQ: CG) is a global investment firm with deep industry expertise that deploys private capital across three business segments: Global Private Equity, Global Credit…” Source: RevenueBase Database · checked Sep 28, 2026
2	H.I.G. Capital	Indirect evidence	Miami, FL, United StatesHQ checked Sep 28, 2026	501-1,000	1,301 contacts →
	Indirect evidence “H.I.G.” Source: RevenueBase Database · checked Sep 28, 2026
3	Warburg Pincus LLC	Indirect evidence	New York, NY, United StatesHQ checked Sep 28, 2026	501-1,000	1,290 contacts →
	Indirect evidence “Warburg Pincus LLC is the pioneer of global growth investing.” Source: RevenueBase Database · checked Sep 28, 2026
4	Golub Capital	Partial evidence	New York, NY, United StatesHQ checked Sep 28, 2026	1,001-5,000	1,126 contacts →
	Partial evidence “Golub Capital is a market-leading, award-winning direct lender and experienced private credit manager.” Source: RevenueBase Database · checked Sep 28, 2026
5	Advent	Indirect evidence	Boston, MA, United StatesHQ checked Sep 28, 2026	501-1,000	1,025 contacts →
	Indirect 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 28, 2026
6	TA Associates	Indirect evidence	Boston, MA, United StatesHQ checked Sep 28, 2026	201-500	881 contacts →
	Indirect evidence “TA is a leading global private equity firm focused on scaling growth in profitable companies.” Source: RevenueBase Database · checked Sep 28, 2026
7	Orix Corporation USA	Indirect evidence	New York, NY, United StatesHQ checked Sep 28, 2026	1,001-5,000	613 contacts →
	Indirect evidence “Established in the U.S.” Source: RevenueBase Database · checked Sep 28, 2026
8	PSG	Indirect evidence	Boston, MA, United StatesHQ checked Sep 28, 2026	51-200	513 contacts →
	Indirect 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 28, 2026
9	Summit Partners	Partial evidence	Boston, MA, United StatesHQ checked Sep 28, 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 28, 2026
10	The Riverside Company	Strong evidence	New York City, NY, United StatesHQ checked Sep 28, 2026	201-500	447 contacts →
	Strong evidence “The Riverside Company is a global investment firm focused on being one of the leading private capital options for business owners and employees at the smaller end of the middle…” Source: RevenueBase Database · checked Sep 28, 2026
11	Cd&r	Partial evidence	New York, NY, United StatesHQ checked Sep 28, 2026	51-200	385 contacts →
	Partial evidence “Founded in 1978, CD & R is an investment firm with an investment strategy predicated on building stronger, more profitable businesses.” Source: RevenueBase Database · checked Sep 28, 2026
12	Adams Street Partners	Strong evidence	Chicago, IL, United StatesHQ checked Sep 28, 2026	201-500	367 contacts →
	Strong evidence “Adams Street Partners is a global investment firm managing a comprehensive suite of private markets investment solutions.” Source: RevenueBase Database · checked Sep 28, 2026
13	NEW Mountain Capital	Partial evidence	New York, NY, United StatesHQ checked Sep 28, 2026	201-500	346 contacts →
	Partial evidence “New Mountain Capital (“New Mountain”) is an alternative investment manager with private equity, credit and net lease strategies.” Source: RevenueBase Database · checked Sep 28, 2026
14	Citizens JMP	Strong evidence	Providence, RI, United StatesHQ checked Sep 28, 2026	10001+	340 contacts →
	Strong evidence “Citizens Capital Markets and Advisory is a leading middle market investment bank that supports clients across a focused set of industry sectors.” Source: RevenueBase Database · checked Sep 28, 2026
15	Midcap Financial	Strong evidence	Bethesda, MD, United StatesHQ checked Sep 28, 2026	201-500	339 contacts →
	Strong evidence “MidCap Financial is a middle-market focused, specialty finance firm that provides senior debt solutions to companies across all industries.” Source: RevenueBase Database · checked Sep 28, 2026
16	W Capital Partners	Indirect evidence	New York, NY, United StatesHQ checked Sep 28, 2026	n/a	337 contacts →
	Indirect evidence “W Capital Partners is a private equity firm that provides secondary liquidity to shareholders in private businesses and growth capital for those companies.” Source: RevenueBase Database · checked Sep 28, 2026
17	Shore Capital Partners	Strong evidence	Chicago, IL, United StatesHQ checked Sep 28, 2026	51-200	327 contacts →
	Strong evidence “Shore Capital, a Chicago-based private equity firm with an office in Nashville, is an investor in lower-middle market companies in the Healthcare, Food and Beverage, Business…” Source: RevenueBase Database · checked Sep 28, 2026
18	Monroe Capital LLC	Partial evidence	Chicago, IL, United StatesHQ checked Sep 28, 2026	201-500	325 contacts →
	Partial evidence “Monroe Capital LLC (“Monroe”) is a premier asset management firm specializing in private credit markets across various strategies, including direct lending, technology finance…” Source: RevenueBase Database · checked Sep 28, 2026
19	HGGC	Indirect evidence	Palo Alto, CA, United StatesHQ checked Sep 28, 2026	51-200	272 contacts →
	Indirect evidence “Since 2007, we’ve specialized in transforming good businesses into great companies through our differentiated approach to partnership investing.” Source: RevenueBase Database · checked Sep 28, 2026
20	Clearlake Capital Group	Indirect evidence	Santa Monica, CA, United StatesHQ checked Sep 28, 2026	51-200	266 contacts →
	Indirect evidence “Clearlake Capital is a leading global alternative asset manager founded in 2006 with over $185 billion of assets under management.” Source: RevenueBase Database · checked Sep 28, 2026
21	Churchill Asset Management	Partial evidence	New York, NY, United StatesHQ checked Sep 28, 2026	201-500	260 contacts →
	Partial evidence “Churchill, an investment-specialist affiliate of Nuveen (the asset manager of TIAA), provides customized financing solutions to U.S.” Source: RevenueBase Database · checked Sep 28, 2026
22	Berkshire Partners	Strong evidence	Boston, MA, United StatesHQ checked Sep 28, 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 28, 2026
23	VFI Corporate Finance	Strong evidence	Salt Lake City, UT, United StatesHQ checked Sep 28, 2026	51-200	249 contacts →
	Strong evidence “VFI finances high-value assets across a wide range of industries, serving middle-market companies.” Source: RevenueBase Database · checked Sep 28, 2026
24	Muzinich & CO	Indirect evidence	New York, NY, United StatesHQ checked Sep 28, 2026	201-500	243 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 28, 2026
25	Gtcr LLC	Indirect evidence	Chicago, IL, United StatesHQ checked Sep 28, 2026	51-200	237 contacts →
	Indirect evidence “Founded in 1980, GTCR is a leading private equity firm that invests behind The Leaders Strategy™ – finding and partnering with management leaders in core domains to identify…” Source: RevenueBase Database · checked Sep 28, 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 investment firms. 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 investment firms.
Partial evidence: Its own public description names part of middle market investment firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name middle market investment firms. 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 4,178 middle market investment firms based in the United States

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Middle market investment firms based in the United States at a glance

As of Sep 28, 2026

51.3%Verified-email coverage

15.4Average contacts per company

1-10Median size (employees)

15.2%Largest-city concentration · New York

Sep 28, 2026Page data refreshed

Companies by employee count

1-10

2,657

11-50

1,198

51-200

226

201-500

501-1,000

1,001-5,000

10001+

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 4,178 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 investment firms, 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 the United States whose own description of what they do matches “middle market investment firms”. 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 investment firms), 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 investment firms, and records with no verified work email. Companies headquartered outside United States 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, 33,107 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 28, 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 investment firms by metro

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 investment firms, 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 investment firms are there based in the United States?

RevenueBase identified 4,178 middle market investment firms headquartered in the 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?

The Carlyle Group, headquartered in Washington, tops this list with the largest team on record.

Which city has the most middle market investment firms?

New York leads with 635 headquartered companies, followed by Chicago (216) and Dallas (178).

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 33,107 verified decision-maker contacts tracked across these 4,178 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 28, 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.