Company lists · Data refreshed September 2026

Top 25 Managed IT security service providers based in the United States

Name: Managed IT security service providers based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 21, 2026 5,478 companies tracked

RevenueBase identified 5,478 managed IT security service providers headquartered in the United States as of September 2026 and tracks 101,670 professional contacts across them, including 45,727 with verified work emails. New York is the largest hub.

This list covers managed IT security service providers 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 21, 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 21, 2026 86% judged on-target in blind review

5,478Companies

101,670Contacts tracked

45,727Verified emails

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The 25 largest managed IT security service providers based in the United States

Ranked by team size

Top 25 of 5,478 managed IT security service providers based in the United States, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to managed IT security service providers: 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	Arctic Wolf	Indirect evidence	Eden Prairie, MN, United StatesHQ checked Sep 21, 2026	1,001-5,000	3,145 contacts →
	Indirect evidence “Every year new technologies, vendors, and solutions emerge-yet despite this constant innovation, high-profile breaches are all over the headlines.” Source: RevenueBase Database · checked Sep 21, 2026
2	Qualys	Strong evidence	Foster City, CA, United StatesHQ checked Sep 21, 2026	1,001-5,000	3,058 contacts →
	Strong evidence “Qualys, Inc.(NASDAQ: QLYS) is a leading provider of disruptive cloud-based security, compliance and IT solutions with more than subscription customers worldwide, including a…” Source: RevenueBase Database · checked Sep 21, 2026
3	Rapid7	Partial evidence	Boston, MA, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,822 contacts →
	Partial evidence “Rapid7, Inc.(NASDAQ: RPD) is a global leader in AI-powered managed cybersecurity operations, trusted to advance organizations’ cyber resilience.” Source: RevenueBase Database · checked Sep 21, 2026
4	Varonis	Partial evidence	Miami, FL, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,715 contacts →
	Partial evidence “Varonis unifies AI-native data security, AI security and governance, and behavior-based threat detection.” Source: RevenueBase Database · checked Sep 21, 2026
5	OPTIV	Indirect evidence	Leawood, KS, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,222 contacts →
	Indirect evidence “Optiv is the cyber advisory and solutions leader, delivering strategic and technical expertise to nearly companies across every major industry.” Source: RevenueBase Database · checked Sep 21, 2026
6	GURU	Strong evidence	Rockville, MD, United StatesHQ checked Sep 21, 2026	n/a	1,906 contacts →
	Strong evidence “Established in 1995, GURU is an IT managed service provider that specializes in infrastructure support, systems integration, data architecture, data hosting, and cloud services.” Source: RevenueBase Database · checked Sep 21, 2026
7	Thales Cybersecurity Products	Indirect evidence	Austin, TX, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,252 contacts →
	Indirect evidence “Thales is a global leader in cybersecurity, helping the most trusted organizations in the world protect their most critical applications, data, and identities anywhere at scale.” Source: RevenueBase Database · checked Sep 21, 2026
8	Guidepoint Security	Partial evidence	Reston, VA, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,232 contacts →
	Partial evidence “GuidePoint Security provides trusted cybersecurity expertise, solutions, and services that help organizations make informed decisions and minimize risk.” Source: RevenueBase Database · checked Sep 21, 2026
9	Watchguard Technologies	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,059 contacts →
	Indirect evidence “WatchGuard® Technologies, Inc.” Source: RevenueBase Database · checked Sep 21, 2026
10	Synoptek	Partial evidence	Costa Mesa, CA, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,037 contacts →
	Partial evidence “Synoptek is a leading global managed services provider and technology consulting firm that delivers transformative business results.” Source: RevenueBase Database · checked Sep 21, 2026
11	Secureworks	Strong evidence	Atlanta, GA, United StatesHQ checked Sep 21, 2026	1,001-5,000	944 contacts →
	Strong evidence “Secureworks, a Sophos Company, empowers organizations worldwide with advanced Managed Detection and Response (MDR) services, our security operations platform Taegis XDR, and…” Source: RevenueBase Database · checked Sep 21, 2026
12	Zerofox	Indirect evidence	Baltimore, MD, United StatesHQ checked Sep 21, 2026	501-1,000	904 contacts →
	Indirect evidence “ZeroFox is the solution to discover, validate, and disrupt external cyber threats before they harm revenue or reputation.” Source: RevenueBase Database · checked Sep 21, 2026
13	Trustwave, A Levelblue Company	Indirect evidence	Chicago, IL, United StatesHQ checked Sep 21, 2026	501-1,000	874 contacts →
	Indirect evidence “Trustwave, a LevelBlue Company, is a globally recognized cybersecurity leader that reduces cyber risk and fortifies organizations against disruptive and damaging cyber threats.” Source: RevenueBase Database · checked Sep 21, 2026
14	Cyderes	Indirect evidence	Kansas City, MO, United StatesHQ checked Sep 21, 2026	1,001-5,000	844 contacts →
	Indirect evidence “Today’s threatscape is relentless.” Source: RevenueBase Database · checked Sep 21, 2026
15	TPX	Indirect evidence	Austin, TX, United StatesHQ checked Sep 21, 2026	1,001-5,000	751 contacts →
	Indirect evidence “TPx is the reliable sidekick every growing business deserves, powering your tech while you take the lead.” Source: RevenueBase Database · checked Sep 21, 2026
16	Huntress	Indirect evidence	Columbia, MD, United StatesHQ checked Sep 21, 2026	501-1,000	696 contacts →
	Indirect evidence “Protect Your Endpoints, Identities, Logs, and Employees.” Source: RevenueBase Database · checked Sep 21, 2026
17	Bluevoyant	Indirect evidence	New York, NY, United StatesHQ checked Sep 21, 2026	501-1,000	683 contacts →
	Indirect evidence “BlueVoyant’s Cyber Defense Platform (CDP) integrates MDR, TPRM, and DRP into a seamless, scalable solution.” Source: RevenueBase Database · checked Sep 21, 2026
18	IT Solutions	Partial evidence	Fort Washington, PA, United StatesHQ checked Sep 21, 2026	501-1,000	683 contacts →
	Partial evidence “With 30 years of experience as a trusted managed services provider, we're your dedicated partner in navigating the complex world of technology, so you can focus on growing your…” Source: RevenueBase Database · checked Sep 21, 2026
19	Network Intelligence	Partial evidence	Plano, TX, United StatesHQ checked Sep 21, 2026	501-1,000	641 contacts →
	Partial evidence “At Network Intelligence, we combine our team of 500+ security professionals with Transilience – our cutting-edge AI platform.” Source: RevenueBase Database · checked Sep 21, 2026
20	Vikingcloud	Indirect evidence	Chicago, IL, United StatesHQ checked Sep 21, 2026	1,001-5,000	628 contacts →
	Indirect evidence “VikingCloud delivers battle-tested cybersecurity and compliance solutions that simply work.” Source: RevenueBase Database · checked Sep 21, 2026
21	Integris	Partial evidence	Cranbury Township, NJ, United StatesHQ checked Sep 21, 2026	501-1,000	574 contacts →
	Partial evidence “Integris is a national leader in future-ready Managed Services, delivering innovative solutions that drive digital maturity for small and midsize businesses.” Source: RevenueBase Database · checked Sep 21, 2026
22	Ultraviolet Cyber	Partial evidence	Mclean, VA, United StatesHQ checked Sep 21, 2026	501-1,000	523 contacts →
	Partial evidence “UltraViolet Cyber is the only security operations partner that unifies red, blue, and purple team capabilities into one integrated program, finding what's vulnerable, stopping…” Source: RevenueBase Database · checked Sep 21, 2026
23	Ntiva, INC	Indirect evidence	Mclean, VA, United StatesHQ checked Sep 21, 2026	501-1,000	505 contacts →
	Indirect evidence “At Ntiva, growing people (our employees, partners, and clients) is our mission.” Source: RevenueBase Database · checked Sep 21, 2026
24	Blue Mantis	Strong evidence	Portsmouth, NH, United StatesHQ checked Sep 21, 2026	201-500	503 contacts →
	Strong evidence “Blue Mantis is a security-first, IT solutions and services provider with a 30+ year history of successfully helping clients achieve business modernization by applying…” Source: RevenueBase Database · checked Sep 21, 2026
25	Vc3	Strong evidence	Columbia, SC, United StatesHQ checked Sep 21, 2026	501-1,000	495 contacts →
	Strong evidence “VC3 is a managed IT and cybersecurity services provider serving organizations throughout the US and Canada.” Source: RevenueBase Database · checked Sep 21, 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: managed IT security service providers. 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 managed IT security service providers.
Partial evidence: Its own public description names part of managed IT security service providers, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name managed IT security service providers. 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 5,478 managed IT security service providers based in the United States

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Managed IT security service providers based in the United States at a glance

As of Sep 21, 2026

45.0%Verified-email coverage

18.6Average contacts per company

1-10Median size (employees)

2.9%Largest-city concentration · New York

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

2,947

11-50

1,877

51-200

466

201-500

501-1,000

1,001-5,000

5,001-10,000

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 5,478 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 managed IT security service providers, 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 “managed IT security service providers”. 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 managed IT security service providers), 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 managed IT security service providers, 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, 45,727 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 21, 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.

Managed IT security service providers 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 managed IT security service providers, 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 managed IT security service providers are there based in the United States?

RevenueBase identified 5,478 managed IT security service providers 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?

Arctic Wolf, headquartered in Eden Prairie, tops this list with the largest team on record.

Which city has the most managed IT security service providers?

New York leads with 160 headquartered companies, followed by Houston (111) and Miami (84).

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 45,727 verified decision-maker contacts tracked across these 5,478 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 21, 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.