United States Clinical Trials Market Size, Share, Trends, and Growth Forecast, 2026-2031 | Outsourcing, AI, and Oncology Propel Market to USD 41.47 Billion
Dublin, Nov. 04, 2026 (GLOBE NEWSWIRE) -- "United States Clinical Trials - Market Share Analysis, Industry Trends & Statistics, Growth Forecasts (2026-2031)" has been added to ResearchAndMarkets.com's offering.
United States Clinical Trials Market to Reach USD 41.47 Billion by 2031
The United States clinical trials market is projected to grow from USD 30.84 billion in 2025 and USD 32.29 billion in 2026 to USD 41.47 billion by 2031. The market is expected to register a CAGR of 5.13% from 2026 to 2031, supported by increased outsourcing, expanding oncology and rare-disease pipelines, greater adoption of advanced trial technologies, and rising demand for integrated clinical trial services.
Outsourcing of Complex Research and Development Programs
Outsourcing remains a major growth driver for the United States clinical trials market. Pharmaceutical, biotechnology, and medical device sponsors are increasingly transferring regulatory operations, safety support, site management, patient services, and post-approval responsibilities to external providers. In March 2026, ACRO reported that member contract research organizations conducted or participated in 7,634 studies involving 1.4 million patients during 2025 while supporting 592 sponsor companies.
The expansion of outsourced responsibilities is creating longer-term relationships between sponsors and clinical research organizations. Providers embedded across multiple development programs are becoming more difficult to replace, increasing demand for partners that combine operational scale, therapeutic expertise, regulatory capabilities, and nationwide site coverage. This trend favors integrated clinical trial service providers over companies offering isolated functions.
Oncology and Rare-Disease Pipelines Support Market Expansion
Oncology continues to generate the largest share of clinical study demand in the United States. IQVIA reported that oncology represented 38% of all Phase I to III industry-sponsored trial starts in 2025. Approximately one-third of these studies involved novel modalities, including antibody-drug conjugates, radiopharmaceutical therapeutics, chimeric antigen receptor gene therapies, and multi-specific antibodies.
These complex programs require specialized site qualification, biomarker screening, cold chain capabilities, intensive safety monitoring, and extended patient follow-up. Rare-disease studies present additional operational challenges because eligible patients are often limited in number and geographically dispersed. This increases the importance of national recruitment programs, flexible site models, and established relationships with high-performing research centers.
AACR reported in 2026 that Phase I non-small cell lung cancer activity had consolidated across 223 US sites by 2024. The concentration of early-stage oncology research reinforces the competitive value of experienced providers with access to specialized investigators, qualified sites, and relevant patient populations.
Patient Recruitment and Retention Remain Key Challenges
Recruitment and retention shortfalls continue to constrain the United States clinical trials market. Frontiers in Medicine reported in 2025 that more than 80% of studies missed their planned recruitment timelines. The Association of Clinical Research Professionals also found that 28% of sites identified recruitment and retention as a leading operational challenge in 2025.
According to IQVIA, median enrollment duration exceeded 16 months in 2025. Delays can increase study costs, extend development schedules, and force sponsors to reopen recruitment campaigns or add research sites. Retention challenges create further financial and operational pressure because participant losses may require studies to over-recruit. In response, sponsors and service providers are placing greater emphasis on patient engagement, retention planning, site support, and more accessible trial participation models.
Additional factors influencing market growth include:
Phase III Maintains the Largest Market Share
Phase III accounted for 48.87% of phase revenue in 2025, making it the largest segment of the United States clinical trials market. Large oncology, cardiovascular, and neurology studies supported this position due to their extensive site networks, central laboratory requirements, long monitoring cycles, and substantial sponsor budgets. Providers with national delivery capabilities and strong site oversight remain well positioned to capture high-value Phase III contracts.
Phase I is forecast to record the fastest phase-based growth, expanding at a CAGR of 7.36% through 2031. IQVIA reported that emerging biopharma companies generated 68% of global Phase I trial starts in 2025. Many of these organizations rely on external partners for first-in-human studies, dose escalation, intensive safety monitoring, and rapid data delivery. Reflecting this demand, ICON opened a new Clinical Research Unit in San Antonio in May 2026 and added satellite outpatient clinics in Houston and Lawrence.
Interventional Studies Lead While Expanded Access Accelerates
Interventional studies represented 69.83% of study design revenue in 2025. Their leading position reflects high volumes of randomized research across oncology, immunology, and cardiovascular disease. These studies require active treatment assignment, protocol compliance, site monitoring, endpoint collection, and direct sponsor oversight, resulting in substantial demand for specialized clinical trial services.
Expanded access is projected to be the fastest-growing study design category, with a CAGR of 7.87% through 2031. FDA guidance published in November 2025 continued to support access pathways for investigational drugs outside formal trial enrollment. These programs require coordinated adverse event reporting, regulatory oversight, safety management, and medical writing. Providers capable of integrating these services into established development workflows are expected to benefit as expanded access programs become a more important component of clinical research in the United States.
Key Topics Covered:
1 Introduction
1.1 Study Assumptions & Market Definition
1.2 Scope of the Study
2 Research Methodology
3 Executive Summary
4 Market Landscape
4.1 Market Overview
4.2 Market Drivers
4.2.1 Outsourcing of Complex R&D Programs
4.2.2 Oncology and Rare-Disease Pipeline Expansion
4.2.3 AI-Enabled Trial Design and Recruitment
4.2.4 Hybrid And Decentralized Trial Adoption
4.2.5 FDA Guidance Clarity for Decentralized Elements
4.2.6 Diversity Action Plan Operationalization
4.3 Market Restraints
4.3.1 Recruitment and Retention Shortfalls
4.3.2 Protocol Complexity and Cost Inflation
4.3.3 Site Technology Overload and PI Attrition
4.3.4 Diversity-Planning Policy Uncertainty
4.4 Value / Supply-Chain Analysis
4.5 Regulatory Landscape
4.6 Technological Outlook
4.7 Porter's Five Forces Analysis
4.7.1 Threat of New Entrants
4.7.2 Bargaining Power of Suppliers
4.7.3 Bargaining Power of Buyers
4.7.4 Threat of Substitutes
4.7.5 Industry Rivalry
5 Market Size & Growth Forecasts
5.1 By Phase
5.1.1 Phase I
5.1.2 Phase II
5.1.3 Phase III
5.1.4 Phase IV
5.2 By Study Design
5.2.1 Interventional
5.2.2 Observational
5.2.3 Expanded Access
5.3 By Indication / Therapeutic Area
5.3.1 Oncology
5.3.1.1 Blood Cancers
5.3.1.2 Solid Tumors
5.3.2 CNS Conditions
5.3.2.1 Epilepsy
5.3.2.2 Parkinson's Disease
5.3.2.3 Stroke
5.3.2.4 Traumatic Brain Injury
5.3.2.5 Amyotrophic Lateral Sclerosis
5.3.3 Autoimmune / Inflammation
5.3.3.1 Rheumatoid Arthritis
5.3.3.2 Multiple Sclerosis
5.3.3.3 Osteoarthritis
5.3.3.4 Irritable Bowel Syndrome
5.3.4 Cardiovascular Diseases
5.3.5 Diabetes
5.3.6 Obesity
5.3.7 Pain Management
5.3.8 Infectious Diseases
5.3.9 Rare Diseases and Orphan Conditions
5.4 By Sponsor
5.4.1 Pharmaceutical Companies
5.4.2 Biotechnology Companies
5.4.3 Medical Device Companies
5.4.4 Academic Medical Centers
5.4.5 Government and Nonprofit Research Organizations
5.5 By Service Type
5.5.1 Protocol Design and Feasibility
5.5.2 Site Identification and Activation
5.5.3 Site Management and Monitoring
5.5.4 Patient Recruitment and Retention
5.5.5 Central Laboratory and Bioanalytical Testing
5.5.6 Clinical Data Management and Biostatistics
5.5.7 Medical Writing and Regulatory Affairs
5.5.8 Pharmacovigilance and Safety
6 Competitive Landscape
6.1 Market Concentration
6.2 Market Share Analysis
6.3 Company Profiles (includes Global level Overview, Market-level Overview, Core Segments, Financials, Strategic Information, Market Rank/Share, Products & Services, Recent Developments)
6.3.1 Advanced Clinical
6.3.2 Allucent
6.3.3 Caidya
6.3.4 Celerion
6.3.5 CenExel
6.3.6 Clario
6.3.7 ICON plc
6.3.8 IQVIA
6.3.9 Labcorp Drug Development
6.3.10 Medidata
6.3.11 Medpace
6.3.12 Parexel International
6.3.13 Rho
6.3.14 Suvoda
6.3.15 Syneos Health
6.3.16 Thermo Fisher Scientific (PPD)
6.3.17 Veristat
7 Market Opportunities & Future Outlook
7.1 White-space & Unmet-need Assessment
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