Company lists · Data refreshed September 2026

Top 25 Due diligence consulting companies based in the United States

RevenueBase identified 249 due diligence consulting companies headquartered in the United States as of September 2026 and tracks 2,601 professional contacts across them, including 1,078 with verified work emails. New York is the largest hub.

This list covers due diligence consulting companies 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 19, 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 19, 2026 86% judged on-target in blind review
249Companies
2,601Contacts tracked
1,078Verified emails
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The 25 largest due diligence consulting companies based in the United States

Ranked by team size
Top 25 of 249 due diligence consulting companies based in the United States, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to due diligence consulting 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.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceHowell, NJ, United StatesHQ checked Sep 19, 2026n/a241 contacts →

Indirect evidence

“We know you work hard to get the best deal possible.”

Source: RevenueBase Database · checked Sep 19, 2026
2Partial evidenceChicago, IL, United StatesHQ checked Sep 19, 202651-200187 contacts →

Partial evidence

“DPO & Co specializes in helping Private Equity firms and their portfolio companies gain fact-based insights during the diligence process and realize post-close synergies and value…”

Source: RevenueBase Database · checked Sep 19, 2026
3Indirect evidenceTampa, FL, United StatesHQ checked Sep 19, 202651-200181 contacts →

Indirect evidence

“Maximizing Value.”

Source: RevenueBase Database · checked Sep 19, 2026
4Strong evidenceBoston, MA, United StatesHQ checked Sep 19, 202651-200168 contacts →

Strong evidence

“For over 25 years, IGS has helped investors and management teams make better, faster decisions, from commercial due diligence, to growth strategy, pricing, and go-to-market…”

Source: RevenueBase Database · checked Sep 19, 2026
5Strong evidenceNew York, NY, United StatesHQ checked Sep 19, 202651-20075 contacts →

Strong evidence

“Blue Heron Research Partners is an international leader in qualitative due diligence.”

Source: RevenueBase Database · checked Sep 19, 2026
6Indirect evidenceMoorestown, NJ, United StatesHQ checked Sep 19, 202651-20068 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 19, 2026
7Strong evidenceMedford, OR, United StatesHQ checked Sep 19, 202611-5067 contacts →

Strong evidence

“Ashland Partners & Company LLP is a PCAOB registered, specialty CPA firm providing due diligence solutions to the investment management industry.”

Source: RevenueBase Database · checked Sep 19, 2026
8Indirect evidenceGrayslake, IL, United StatesHQ checked Sep 19, 202651-20064 contacts →

Indirect evidence

“LM Consultants, Inc.”

Source: RevenueBase Database · checked Sep 19, 2026
9Indirect evidenceCincinnati, OH, United StatesHQ checked Sep 19, 202611-5062 contacts →

Indirect evidence

“Live investigator-led analysis is the best way to minimize regulatory, reputational and financial risks.”

Source: RevenueBase Database · checked Sep 19, 2026
10Strong evidenceSanta Monica, CA, United StatesHQ checked Sep 19, 202651-20049 contacts →

Strong evidence

“Ironsides is an M&A advisory firm focused exclusively on providing transaction services including financial and accounting due diligence, tax due diligence and structuring…”

Source: RevenueBase Database · checked Sep 19, 2026
11Strong evidenceDallas, TX, United StatesHQ checked Sep 19, 202651-20049 contacts →

Strong evidence

“Columbia Advisory Group is a Dallas, Texas based Information Technology consulting firm focused on providing Information Technology due diligence, strategic assessment and…”

Source: RevenueBase Database · checked Sep 19, 2026
12Strong evidenceLos Angeles, CA, United StatesHQ checked Sep 19, 20261,001-5,00047 contacts →

Strong evidence

“On the leading edge of innovation in commercial real estate transactions, GRS an NV5 Company is one of the largest national provider CRE due diligence services.”

Source: RevenueBase Database · checked Sep 19, 2026
13Strong evidenceNew York, NY, United StatesHQ checked Sep 19, 202651-20042 contacts →

Strong evidence

“Hilton Global Associates is a professional investigative research firm providing expert due diligence and unparalleled client service.”

Source: RevenueBase Database · checked Sep 19, 2026
14Strong evidenceBoston, MA, United StatesHQ checked Sep 19, 202611-5037 contacts →

Strong evidence

“Fairmont Consulting Group is a Boston-based firm focused on due diligence and strategic advisory services for clients active in aerospace, defense, government services, and the…”

Source: RevenueBase Database · checked Sep 19, 2026
15Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 19, 202611-5037 contacts →

Partial evidence

“CDS is now part of CrossCountry Consulting.”

Source: RevenueBase Database · checked Sep 19, 2026
16Indirect evidenceVienna, VA, United StatesHQ checked Sep 19, 202611-5033 contacts →

Indirect evidence

“Pipaya has joined Prosperity Partners!”

Source: RevenueBase Database · checked Sep 19, 2026
17Strong evidenceColumbia, MD, United StatesHQ checked Sep 19, 202611-5027 contacts →

Strong evidence

“Our law firm combines highly specialized legal expertise with business and financial acumen, which allows us to provide our clients with focused intelligence and due diligence on…”

Source: RevenueBase Database · checked Sep 19, 2026
18Indirect evidenceEden Prairie, MN, United StatesHQ checked Sep 19, 202611-5022 contacts →

Indirect evidence

“FactRight is the premier source of credible perspective and advice for wealth managers seeking access to alternative investments.”

Source: RevenueBase Database · checked Sep 19, 2026
19Strong evidenceDallas/fort Worth, MI, United StatesHQ checked Sep 19, 202611-5020 contacts →

Strong evidence

“SCA Transaction Services LLC provides accounting due diligence and other transaction advisory services to private equity groups, lenders and corporations.”

Source: RevenueBase Database · checked Sep 19, 2026
20Indirect evidenceArlington, VA, United StatesHQ checked Sep 19, 202611-5019 contacts →

Indirect evidence

“We have helped dozens of clients gain insight into critical areas of concern by thoroughly reviewing their target company’s information and asking intelligent questions.”

Source: RevenueBase Database · checked Sep 19, 2026
21Strong evidenceSeattle, WA, United StatesHQ checked Sep 19, 202611-5019 contacts →

Strong evidence

“Tech DNA Is a global leader in technology due diligence.”

Source: RevenueBase Database · checked Sep 19, 2026
22Indirect evidenceChicago, IL, United StatesHQ checked Sep 19, 202611-5018 contacts →

Indirect evidence

“Founded in 1991, GTG Consultants, Inc.”

Source: RevenueBase Database · checked Sep 19, 2026
23Strong evidenceNashville, TN, United StatesHQ checked Sep 19, 202611-5018 contacts →

Strong evidence

“Moore-McNeil, LLC (“Moore-McNeil”) is an insurance consulting firm with extensive experience in providing due diligence and outsourced risk management services.”

Source: RevenueBase Database · checked Sep 19, 2026
24Strong evidenceDallas, TX, United StatesHQ checked Sep 19, 202611-5017 contacts →

Strong evidence

“Targus Associates specializes in environmental due diligence services for acquisitions and financing of commercial real estate and related consulting services.”

Source: RevenueBase Database · checked Sep 19, 2026
25Strong evidenceNew York, NY, United StatesHQ checked Sep 19, 202611-5016 contacts →

Strong evidence

“Since 1998, Velocity Consulting, Inc.(“Velocity”) has provided a full range of real estate due diligence services including Phase I ESAs, Property Condition Assessments…”

Source: RevenueBase Database · checked Sep 19, 2026

Showing 25 of 249 due diligence consulting companies based in the United States

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Due diligence consulting companies based in the United States at a glance

As of Sep 19, 2026
41.4%Verified-email coverage
10.4Average contacts per company
1-10Median size (employees)
8.8%Largest-city concentration · New York
Sep 19, 2026Page data refreshed

Companies by employee count

1-10
159
11-50
73
51-200
16
1,001-5,000
1

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 249 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 due diligence consulting 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 the United States whose own description of what they do matches “due diligence consulting 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 due diligence consulting 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 due diligence consulting companies, 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, 1,078 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 19, 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.

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 due diligence consulting 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 due diligence consulting companies are there based in the United States?

RevenueBase identified 249 due diligence consulting companies 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?

Gparency, headquartered in Howell, tops this list with the largest team on record.

Which city has the most due diligence consulting companies?

New York leads with 22 headquartered companies, followed by Chicago (12) and Los Angeles (8).

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 1,078 verified decision-maker contacts tracked across these 249 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 19, 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.