Company lists · Data refreshed September 2026

Top 25 Clinical research staffing agencies based in the United States

Name: Clinical research staffing agencies based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 27, 2026 2,968 companies tracked

RevenueBase identified 2,968 clinical research staffing agencies headquartered in the United States as of September 2026 and tracks 157,687 professional contacts across them, including 61,045 with verified work emails. New York is the largest hub.

This list covers clinical research staffing agencies 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 27, 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 27, 2026 86% judged on-target in blind review

2,968Companies

157,687Contacts tracked

61,045Verified emails

Explore this list → Free signup · no credit card · 500 free credits

The 25 largest clinical research staffing agencies based in the United States

Ranked by team size

Top 25 of 2,968 clinical research staffing agencies based in the United States, ranked by team size, largest first. Data refreshed Sep 27, 2026. RevenueBase Smart Search rates how each company's information relates to clinical research staffing agencies: 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	PPD	Strong evidence	Waltham, MA, United StatesHQ checked Sep 27, 2026	10001+	20,530 contacts →
	Strong evidence “The PPD™ clinical research business of Thermo Fisher Scientific, the world leader in serving science, enables customers to accelerate innovation and drug development through…” Source: RevenueBase Database · checked Sep 27, 2026
2	Parexel	Strong evidence	Raleigh, NC, United StatesHQ checked Sep 27, 2026	10001+	19,257 contacts →
	Strong evidence “Parexel is a leading global clinical research organization (CRO) providing insights-driven Clinical and Consulting solutions to the world’s life sciences industry.” Source: RevenueBase Database · checked Sep 27, 2026
3	Fortrea	Strong evidence	Research Triangle Park, NC, United StatesHQ checked Sep 27, 2026	10001+	10,632 contacts →
	Strong evidence “Fortrea (Nasdaq: FTRE) is a leading global clinical research organization (CRO) dedicated to providing innovative clinical development solutions to the life sciences industry.” Source: RevenueBase Database · checked Sep 27, 2026
4	Medpace	Strong evidence	Cincinnati, OH, United StatesHQ checked Sep 27, 2026	5,001-10,000	5,960 contacts →
	Strong evidence “Medpace is a scientifically-driven, global, full-service clinical contract research organization (CRO) providing Phase I-IV clinical development services to the biotechnology…” Source: RevenueBase Database · checked Sep 27, 2026
5	Worldwide Clinical Trials	Partial evidence	Research Triangle Park, NC, United StatesHQ checked Sep 27, 2026	1,001-5,000	3,440 contacts →
	Partial evidence “Worldwide Clinical Trials (Worldwide) is a global CRO serving development-driven biopharmaceutical companies, with more than 4,400 professionals operating across more than 70…” Source: RevenueBase Database · checked Sep 27, 2026
6	Premier Research	Strong evidence	Morrisville, NC, United StatesHQ checked Sep 27, 2026	1,001-5,000	2,584 contacts →
	Strong evidence “Premier Research International LLC (Premier) is a global leader in clinical research and consulting services with expertise in driving an efficient and effective path to market…” Source: RevenueBase Database · checked Sep 27, 2026
7	Signant Health	Strong evidence	Blue Bell, PA, United StatesHQ checked Sep 27, 2026	1,001-5,000	2,083 contacts →
	Strong evidence “For 25+ years, Signant Health has been pioneering solutions and methodologies that propel clinical research programs toward regulatory success.” Source: RevenueBase Database · checked Sep 27, 2026
8	Propharma	Indirect evidence	Raleigh, NC, United StatesHQ checked Sep 27, 2026	1,001-5,000	2,079 contacts →
	Indirect evidence “At ProPharma, we help pharmaceutical, biotechnology, and medical device companies bring life-changing therapies to market.” Source: RevenueBase Database · checked Sep 27, 2026
9	Precision For Medicine	Strong evidence	Bethesda, MD, United StatesHQ checked Sep 27, 2026	1,001-5,000	1,781 contacts →
	Strong evidence “Precision for Medicine is an industry-leading global clinical research services organization, purpose-built to improve the clinical research and development process for new…” Source: RevenueBase Database · checked Sep 27, 2026
10	CYTEL	Partial evidence	Cambridge, MA, United StatesHQ checked Sep 27, 2026	1,001-5,000	1,580 contacts →
	Partial evidence “Cytel is the world’s leading data-science CRO, driving advancements in human health through robust analytics and innovative clinical trial software.” Source: RevenueBase Database · checked Sep 27, 2026
11	Triage Staffing Healthcare Staffing	Indirect evidence	Omaha, NE, United StatesHQ checked Sep 27, 2026	n/a	1,538 contacts →
	Indirect evidence “In recruiting, stating actual facts has become: Foreign \| Uncommon \| Taboo.” Source: RevenueBase Database · checked Sep 27, 2026
12	locumtenens.com	Partial evidence	Alpharetta, GA, United StatesHQ checked Sep 27, 2026	501-1,000	1,171 contacts →
	Partial evidence “LocumTenens.com specializes in optimizing healthcare staffing operations.” Source: RevenueBase Database · checked Sep 27, 2026
13	Totalmed	Partial evidence	Appleton, WI, United StatesHQ checked Sep 27, 2026	201-500	1,170 contacts →
	Partial evidence “TotalMed provides temporary, contract, and full time staffing services to hospitals, medical groups, health plans, and life sciences companies who require staffing assistance in…” Source: RevenueBase Database · checked Sep 27, 2026
14	Planet Pharma	Partial evidence	Raleigh, NC, United StatesHQ checked Sep 27, 2026	1,001-5,000	1,088 contacts →
	Partial evidence “Founded in 2012, Planet Pharma is a global leader in life sciences recruitment and staffing, specializing in Pharmaceuticals, Biotechnology, Medical Device, Labs & Healthcare…” Source: RevenueBase Database · checked Sep 27, 2026
15	CTI Clinical Trial And Consulting Services	Strong evidence	Covington, KY, United StatesHQ checked Sep 27, 2026	1,001-5,000	1,043 contacts →
	Strong evidence “CTI Clinical Trial and Consulting Services is a global, privately held, research service organization, delivering a complete spectrum of clinical trial and consulting services…” Source: RevenueBase Database · checked Sep 27, 2026
16	Navitas Life Sciences	Strong evidence	Gaithersburg, MD, United StatesHQ checked Sep 27, 2026	1,001-5,000	990 contacts →
	Strong evidence “Navitas Life Sciences is a global Clinical Research partner with over 35 years of expertise in Clinical, Regulatory, Safety, and Data Management solutions.” Source: RevenueBase Database · checked Sep 27, 2026
17	Velocity Clinical Research, INC	Strong evidence	Durham, NC, United StatesHQ checked Sep 27, 2026	1,001-5,000	971 contacts →
	Strong evidence “Velocity is the world’s leading organization of fully integrated clinical research sites.” Source: RevenueBase Database · checked Sep 27, 2026
18	EMMES	Strong evidence	Rockville, MD, United StatesHQ checked Sep 27, 2026	1,001-5,000	961 contacts →
	Strong evidence “Emmes is a Contract Research Organization delivering complex clinical trials through therapeutic expertise, scientific rigor, and technology-enabled execution.” Source: RevenueBase Database · checked Sep 27, 2026
19	Advanced Clinical	Partial evidence	Deerfield, IL, United StatesHQ checked Sep 27, 2026	501-1,000	960 contacts →
	Partial evidence “Advanced Clinical is a clinical development and strategic resourcing organization committed to providing a better clinical experience across the drug development journey.” Source: RevenueBase Database · checked Sep 27, 2026
20	Grapetree Medical Staffing	Partial evidence	Milford, IA, United StatesHQ checked Sep 27, 2026	n/a	957 contacts →
	Partial evidence “GrapeTree Medical Staffing has over 25 years of experience offering 24/7 staffing solutions to healthcare communities.” Source: RevenueBase Database · checked Sep 27, 2026
21	Bioagilytix	Partial evidence	Durham, NC, United StatesHQ checked Sep 27, 2026	1,001-5,000	915 contacts →
	Partial evidence “BioAgilytix is a leading global contract research organization focused on supporting pharmaceutical and biotech partners in all phases of drug development.” Source: RevenueBase Database · checked Sep 27, 2026
22	Imcs Group	Partial evidence	Irving, TX, United StatesHQ checked Sep 27, 2026	201-500	881 contacts →
	Partial evidence “IMCS Group is an IT, Healthcare, and Professional Staffing Company that helps Enterprises optimize the business value of their Staffing investments and enables them to achieve…” Source: RevenueBase Database · checked Sep 27, 2026
23	MMS	Strong evidence	Canton, MI, United StatesHQ checked Sep 27, 2026	501-1,000	876 contacts →
	Strong evidence “MMS Holdings (MMS) is an award-winning, data-focused clinical research organization (CRO) that supports the pharmaceutical and biotech industries with a proven, scientific…” Source: RevenueBase Database · checked Sep 27, 2026
24	Medpro Healthcare Staffing	Partial evidence	Fort Lauderdale, FL, United StatesHQ checked Sep 27, 2026	501-1,000	855 contacts →
	Partial evidence “MedPro Healthcare Staffing is a Joint Commission certified, leading provider of temporary and contract staffing services to healthcare facilities throughout the United States.” Source: RevenueBase Database · checked Sep 27, 2026
25	Cenexel	Strong evidence	Salt Lake City, UT, United StatesHQ checked Sep 27, 2026	1,001-5,000	847 contacts →
	Strong evidence “CenExel is a leading integrated, wholly owned, nationwide clinical research site network comprised of 18 Centers of Excellence in major metropolitan areas across the U.” Source: RevenueBase Database · checked Sep 27, 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: clinical research staffing agencies. 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 clinical research staffing agencies.
Partial evidence: Its own public description names part of clinical research staffing agencies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name clinical research staffing agencies. 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 2,968 clinical research staffing agencies based in the United States

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 61,045 reachable decision-makers.

Free signup · no credit card

View the full list →

Clinical research staffing agencies based in the United States at a glance

As of Sep 27, 2026

38.7%Verified-email coverage

53.1Average contacts per company

11-50Median size (employees)

3.3%Largest-city concentration · New York

Sep 27, 2026Page data refreshed

Companies by employee count

1-10

1,233

11-50

918

51-200

521

201-500

154

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 2,968 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 clinical research staffing agencies, 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 “clinical research staffing agencies”. 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 clinical research staffing agencies), 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 clinical research staffing agencies, 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, 61,045 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 27, 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.

Clinical research staffing agencies 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 clinical research staffing agencies, 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 clinical research staffing agencies are there based in the United States?

RevenueBase identified 2,968 clinical research staffing agencies 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?

PPD, headquartered in Waltham, tops this list with the largest team on record.

Which city has the most clinical research staffing agencies?

New York leads with 98 headquartered companies, followed by Miami (65) and Houston (60).

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 61,045 verified decision-maker contacts tracked across these 2,968 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 27, 2026.

Ready to reach these companies? Verified emails and direct dials for all 2,968 clinical research staffing agencies based in the United States. Start with a free account, no credit card.

Download this list →

Related lists

Clinical research staffing agencies by geography

Browse the directory

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.