Diversity in Clinical Trial Recruitment: Enrollment Data, FDA Requirements, and Strategies for 2026

Diversity in clinical trials measures how closely a study's participants match the population that actually carries the disease under investigation, broken out by race, ethnicity, sex, and age. That benchmark differs from the country's overall demographics, and the FDA and Congress now regulate it directly. Only 6% of 341 Phase III pivotal trials run between 2017 and 2023 achieved enrollment matching the four largest US racial and ethnic groups, according to a December 2025 study in Communications Medicine. This article compiles the current enrollment data by demographic group, explains what the FDA's Diversity Action Plan rule requires, covers why representation gaps persist even as reporting compliance has improved, and lays out the recruitment strategies sponsors are using to close the gap, including community engagement, decentralized trial design, and technology-assisted screening.

The state of clinical trial diversity in one table

Federal Drug Trials Snapshots reports and peer-reviewed studies published between 2023 and 2026 show that clinical trial enrollment has not matched US disease prevalence for every demographic group, despite more than a decade of federal reporting requirements. The table below summarizes the headline figures referenced throughout this article.

Representation has not caught up with the populations most affected by the diseases under study. That gap holds across race, ethnicity, and age, even as reporting compliance itself has improved sharply.

Who actually enrolls in US clinical trials

The FDA's three most recent Drug Trials Snapshots reports count roughly 101,000 pivotal-trial participants across 151 novel drug approvals from 2023 through 2025. Sex balance varies widely by therapeutic area, and gaps by race, ethnicity, and age against disease burden persist.

In the FDA 2025 Drug Trials Snapshots Summary Report, roughly 26,000 participants took part in the pivotal trials supporting 46 novel drug approvals, and female participation across individual drug programs ranged from 9% to 99%. The 2024 report counted roughly 31,000 participants across 50 novel drug approvals, with female participation by program ranging from 9% to 98%. The 2023 report covered roughly 44,000 participants across 55 novel drug approvals. The reports summarize sex by therapeutic area and exclude sex-specific indications, rather than publishing one aggregate split.

By race and ethnicity, the gap is sharper. A JAMA Network Open study published July 3, 2023 found that among eligible US oncology patients from 2017 to 2022, only 4.4% of Black patients (307 of 6,912) and 4.2% of Latinx patients (166 of 3,973) enrolled in a trial, compared with 7.2% of White patients (2,858 of 39,526). The adjusted hazard ratio for Black versus White trial participation fell from 0.61 in 2017 to 2019 to 0.49 in 2020 to 2022. That means the participation gap widened rather than closed over the study period.

Age carries its own gap. A JAMA study published December 11, 2023 reviewed 85 FDA-approved oncology indications from 2015 to 2021 and found adequate representation, meaning enrollment proportional to disease burden, in 82% of trials for women, 73% for Asian patients, 46% for adults 65 and older, 27% for Hispanic or Latino patients, and 11% for Black patients. The same study found no statistically significant difference in clinical development time between adequately and inadequately represented trials.

Publicly funded research tells a different story. The NIAID FY2022-2024 Triennial Inclusion Report shows minority enrollment across NIAID-supported clinical research at 54.2% in FY2022, 61.0% in FY2023, and 71.7% in FY2024, with female enrollment rising from 45.4% to 49.3% over the same period. Black or African American enrollment at US sites was 17.0% in FY2022, split 26.6% female and 22.9% male in FY2023, and 14.1% female and 18.7% male in FY2024.

The gap between NIH-funded and industry-sponsored enrollment traces back three decades. The NIH Revitalization Act of 1993 first required NIH-funded research to include women and underrepresented racial and ethnic groups. That mandate never extended to industry-sponsored trials, which produce most of the pivotal data behind drug approvals. FDORA, enacted in 2022, is the first statute to impose a comparable recruitment requirement on industry sponsors.

Enrollment versus disease prevalence: the representation gap

Even when a demographic group is present in a trial, its share is often smaller than its share of the people who actually have the disease being studied.

A Contemporary Clinical Trials Communications study published in April 2024 compared 17 US-only FDA approval trials from 2017 to 2020 against real-world prevalence data covering more than 150 million patients. Only 38 of 85 demographic cohorts studied, 45%, fell within the 0.75 to 1.25 ratio band researchers considered acceptable representation. Asian patients were underrepresented in 11 of the 17 trials, the most of any group studied. Black or African American patients were underrepresented in 6 of the 17.

An HHS ASPE Issue Brief published October 16, 2024 found a similar pattern across 29,318 participants in 391 trials for eight rare cancers completed between 2004 and 2023. Hispanic or Latino participation ran 33 to 52 percentage points below disease incidence, and Black participation ran 3 to 19 percentage points below incidence, depending on the cancer studied.

The same ASPE brief found reporting practices have improved even where representation has not. A federal requirement to report race and ethnicity data to ClinicalTrials.gov took effect in April 2017. Among the rare-cancer trials studied, race reporting rose from 38% before that date to 90% after, and ethnicity reporting rose from 27% to 63%. Accrual of participants from underrepresented groups in the National Cancer Institute's NCTN and NCORP networks rose from 14% in 1999 to 2001 to 25% in 2017 to 2019. Female participation in the rare-cancer trials still ran 15 percentage points below the FDA's own 2015 to 2019 Drug Trials Snapshots aggregate baseline.

What the FDA now requires: Diversity Action Plans

The Food and Drug Omnibus Reform Act, or FDORA, requires sponsors of certain drug, biologic, and device trials to submit a Diversity Action Plan to FDA ahead of a pivotal study. FDORA became law in December 2022 as part of the Consolidated Appropriations Act, 2023. The requirement sits in section 3601 of FDORA, which added sections 505(z) and 520(g) to the Federal Food, Drug, and Cosmetic Act. Section 3602 directs FDA to issue guidance on the plans' format and content.

On June 26, 2024, FDA published draft guidance describing what a Diversity Action Plan must contain, with a formal Federal Register notice published June 28, 2024. Under that draft, a plan must state enrollment goals broken out by age, sex, race, and ethnicity, the disease-prevalence or incidence data behind those goals, and the specific measures a sponsor will use to meet them. The public comment period on the draft guidance closed September 26, 2024.

The guidance's status has changed several times since. FDA removed the draft guidance from its website on January 23, 2025, following a presidential executive order on federal diversity, equity, and inclusion policy, according to a Crowell & Moring client alert. A federal judge ordered HHS, FDA, and CDC to restore the removed pages. The Diversity Action Plan guidance was restored on February 11 to 12, 2025, following a ruling in Doctors for America v. Office of Personnel Management in the US District Court for the District of Columbia, as reported by NPR and confirmed by Citeline/HBW Insight.

The litigation has since concluded. On July 3, 2025, the same court issued a final ruling that vacated the federal directives behind the removals and ordered the affected pages restored, as reported by Fierce Healthcare. As of this article's publish date, the draft guidance remains posted on FDA's website, labeled a draft that is not for implementation and carrying a notice that the page was restored under court order. FDA has not issued a final version, despite a statutory deadline of June 26, 2025 for final guidance under FDORA. The underlying FDORA statutory requirement to submit a Diversity Action Plan remains in force throughout; only the guidance describing its expected form and content has been removed and restored.

The DEPICT Act, the Diverse and Equitable Participation in Clinical Trials Act, is the bill Representatives Anna Eshoo, Brian Fitzpatrick, and Robin Kelly introduced in February 2022; it never passed as standalone law, and Congress instead enacted a comparable diversity-action-plan mandate through FDORA when FDORA passed in December 2022. The enforceable requirement sponsors face today for recruitment planning runs through FDORA sections 3601 and 3602 rather than through the DEPICT Act as a separate, standalone statute. Trade press and legal analysis sometimes still reference the DEPICT Act by name when describing the diversity action plan mandate, which can read like a second, parallel requirement; sponsors should treat FDORA sections 3601 and 3602 as the current, controlling text rather than researching DEPICT Act compliance separately. Sponsors building 2026 recruitment plans should verify that directly against current congressional and FDA sources before relying on it.

Why representation gaps persist

Researchers most often point to four structural factors: trial-site geography, eligibility criteria, trust, and access and cost.

Pivotal trials concentrate at large academic medical centers, which are not evenly distributed relative to where underrepresented populations live, according to the HHS ASPE Issue Brief. A patient who lives hours from the nearest trial site faces a structural barrier to enrollment regardless of eligibility or interest.

Broad exclusion criteria screen out a larger share of patients from populations with higher rates of untreated comorbid conditions. Common examples include comorbidity limits, prior-treatment restrictions, and organ-function thresholds. FDA's November 2020 guidance on broadening eligibility criteria recommends designing trials to reflect the population expected to use the eventual approved drug, and it predates the FDORA Diversity Action Plan requirement. In December 2025, FDA reissued that guidance as final guidance titled Enhancing Participation in Clinical Trials. The new title removes the word diversity, but the guidance still recommends enrolling trial populations that reflect the patients likely to take the drug if it is approved.

Trust is a documented factor in the clinical-trials literature: historical research practices have left some populations with a lower baseline willingness to enroll, independent of eligibility or access. Researchers treat trust as one of several contributing factors, not the primary driver. Rebuilding that trust has become a defined part of recruitment strategy, not just an ethical aside, for sponsors building enrollment plans in 2026.

Out-of-pocket costs remain a barrier even though the Affordable Care Act requires routine-care costs for trial participants to be covered; travel and childcare costs are not included in that requirement. The ASPE brief names these costs as a continuing access barrier separate from eligibility criteria. Sponsors track a related metric on their own side of the ledger: the per-patient cost and timeline impact of slow enrollment, which grows the longer a Diversity Action Plan's enrollment goals go unmet.

Recruitment strategies that close the diversity gap

Closing the diversity gap in trial enrollment now runs through four recruitment levers. Sponsors combine community engagement versus paid digital outreach, decentralized and hybrid trial design under FDORA's Diversity Action Plan mandate, trust-building with underrepresented communities, and AI-assisted recruitment paired with traditional physician referral.

Expanding where and how a trial recruits changes who has practical access to enroll, independent of eligibility criteria. That includes adding more sites, decentralized or remote elements, translated materials, and community-based locations.

Research on decentralized trial elements shows these changes most reliably widen geographic and site-level reach; evidence on whether they specifically close racial and ethnic representation gaps is still developing and mixed. Community-based and rural sites extend a trial's footprint beyond the academic medical centers where pivotal trials have historically concentrated. Multilingual materials remove a practical barrier for patients who would otherwise be excluded by language alone, independent of their eligibility on clinical grounds.

Community engagement and paid digital outreach solve different parts of the recruitment problem, and sponsors increasingly run both rather than choosing one. Community engagement means partnering with patient advocacy groups, faith organizations, and community health centers. It tends to cost more per contact and scale more slowly, but it reaches patients who distrust cold digital advertising and whom a paid campaign alone would never surface. Digital and social outreach scales faster and reaches a wider geographic radius at a lower cost per impression. But conversion quality varies by platform and creative, and it depends on patients already searching for or receptive to trial information. Sponsors building 2026 enrollment plans increasingly sequence the two: digital outreach for volume, community engagement for the populations digital channels reliably miss.

Community-based recruitment often runs through paid outreach and social channels. Before enrollment even starts, a sponsor or site has to satisfy the IRB and platform rules that govern recruitment advertising, which set real limits on what can be said to a prospective participant regardless of which demographic group the site is trying to reach.

Algorithmic patient matching tools screen electronic health records against trial eligibility criteria simultaneously. That surfaces candidates a manual chart review would take a coordinator days to find, and some platforms cross-reference multiple open studies at once rather than one trial at a time. Traditional recruitment still produces some of the highest-trust leads, since a recommendation from a patient's own doctor carries more weight than a match from a tool the patient has never heard of. That approach relies on referrals from treating physicians and manual chart review. Evidence is still developing and mixed on whether AI-assisted matching specifically narrows racial and ethnic representation gaps, rather than simply speeding up recruitment overall. That echoes the same open question researchers raise about decentralized trial design generally.

Concrete trust-building tactics move beyond acknowledging the trust gap in underrepresented communities into practice. Community advisory boards seat members from the populations a trial is trying to reach. They give sponsors a standing channel for feedback before and during enrollment, not just after a study ends. Translated informed-consent materials remove a barrier that generic multilingual translation alone does not solve. The materials need review for cultural context, not word-for-word conversion. Transparent data-sharing commitments address the historical grievance that research extracted information without returning value. That means telling a community what a trial found and how the findings will be used.

Patient advocacy groups add a fifth channel sponsors underuse: an advocacy group with an existing, engaged community can put a trial in front of patients who already trust the organization. That closes outreach gaps that paid advertising and even community advisory boards do not reach on their own.

Sponsors trying to close a demographic gap on a live trial rarely start from a blank page; many first look at how specialist agencies have solved site-diversity and channel mix on a comparable study. Eligibility criteria and site-selection choices set the outer bounds of who can enroll; channel and outreach choices determine who within those bounds actually hears about the trial.

What the data means for 2026 and 2027 trial planning

Reporting on clinical trial demographics has improved sharply since federal race and ethnicity reporting requirements took effect in April 2017: race reporting in the rare-cancer trials HHS studied rose from 38% to 90%. Representation itself, measured against both US demographics and disease-specific prevalence, has not kept pace with that reporting gain. The FDORA statutory requirement to submit a Diversity Action Plan, the same requirement the DEPICT Act originated, has remained in force through the guidance's publication, removal, and court-ordered restoration. Sponsors building 2026 and 2027 trial designs should expect the requirement to bind eventually, even without a final guidance document in place today. Execution moves enrollment numbers; paperwork alone does not. Community engagement, decentralized trial design, trust-building, and technology-assisted screening will do more to close representation gaps than any single guidance update.

Frequently asked questions

Why does diversity in clinical trial recruitment matter?

Diversity in clinical trial recruitment matters because trial results only generalize to patients who resemble the people enrolled. Safety and efficacy data behind an approved drug reflects a narrower population than the one that eventually takes it, according to a JAMA Network Open study. Black patients enrolled in oncology trials at 4.4% versus 7.2% for White patients from 2017 to 2022, and the adjusted hazard ratio for Black-versus-White participation fell from 0.61 to 0.49 over that period.

What are the FDA requirements for diversity in clinical trials?

FDA requires sponsors of certain drug, biologic, and device trials to submit a Diversity Action Plan under FDORA sections 3601 and 3602, the same diversity action plan mandate the DEPICT Act originated. FDA published draft guidance on the plan's required format on June 26, 2024; that guidance was removed in January 2025, restored by court order in February 2025, and remains posted as a draft, not a final rule, as of this article's publish date. The underlying statutory requirement stays in force regardless of the guidance's draft status.

What percentage of clinical trial participants are from underrepresented groups?

It varies widely by disease and group. A 2025 Communications Medicine study found only 6% of 341 Phase III pivotal trials (2017 to 2023) matched US racial and ethnic demographics, and just 23% adequately represented Black participants and 30% adequately represented Hispanic participants in 2023 trials specifically.

What are the biggest barriers to diverse clinical trial enrollment?

Researchers point to four recurring barriers to diverse clinical trial enrollment. They are eligibility criteria broad enough to screen out patients with common comorbidities, trust deficits tied to historical research practices that lower some populations' baseline willingness to enroll, out-of-pocket costs the Affordable Care Act does not fully cover, and trial sites concentrated at large academic medical centers far from where many underrepresented populations actually live.

How do you recruit more diverse clinical trial participants?

Sponsors close diversity gaps by combining several recruitment tactics at once. Those tactics are community engagement through partnerships with patient advocacy groups, faith organizations, and community health centers, paid digital outreach for scale, decentralized or hybrid site design that reaches patients living far from academic medical centers, translated and culturally adapted materials rather than direct translations, and broadened eligibility criteria that reflect the population a drug will eventually treat once approved.