Patients often do not know how to locate appropriate studies. The most comprehensive public registry is clinicaltrials.gov, but searching requires matching many patient characteristics and contacting sites to confirm availability. Disease-focused organizations and advocacy groups offer matching services and navigators; examples include the American Cancer Society’s clinical trial matching service and disease-specific listings from groups like the Arthritis Foundation and the National Multiple Sclerosis Society.
Many clinicians do not routinely refer patients. In a survey of primary care physicians sponsored by the Patient Advocate Foundation, most said they were likely to refer patients to trials but far fewer had actually done so. When clinicians do discuss trials, it is often because the patient raised the topic, standard treatments were failing, or disease was progressing.
If a trial is active at a hospital or facility where a patient is already treated, that patient is often best positioned to enroll. Patients should ask their doctor or facility staff whether any trials are open onsite and how to contact the trial team.
Clinical trials can test new drugs, devices, preventive measures, diagnostic approaches, and lifestyle interventions. For people with serious illnesses, a trial may offer access to experimental therapies that could extend life or improve quality of life. Even participants who do not receive the investigational therapy typically receive close monitoring and high-quality care during the trial.
Some people join trials to help advance science or to contribute to knowledge that may benefit others. Observational studies also provide important data—for example, volunteers undergoing cognitive testing and brain scans can help researchers track disease progression and identify early changes.
Much U.S. clinical research takes place at large academic or urban medical centers. That concentration limits access for people treated elsewhere who would need to travel frequently for visits, blood draws, imaging, or other study procedures. Decentralized trial approaches—conducting some tasks at home or at a local center—are being explored but remain uncommon.
Evidence of geographic barriers is substantial: a 2019 study of 8,893 cancer patients found that 55.6% did not have an available trial for their cancer type and stage at the facility where they were treated. An additional 21.5% were not eligible for available trials at their site. Site availability and proximity are therefore primary obstacles to participation.
Meeting a trial’s inclusion and exclusion criteria is a major gatekeeper. Even when a trial exists, patients must reach out to trial recruiters and determine whether they meet eligibility requirements. The process can be time-consuming for clinicians to manage: a community oncologist may need to search registries, screen potential trials for fit, and contact sites to confirm status, all of which can compete with routine clinical responsibilities.
Retention is another concern: recruitment into a trial does not guarantee completion. Investigators and patient advocates emphasize that every touchpoint—enrollment, follow-up visits, and study procedures—can present access or affordability problems that threaten retention.
Trial sponsors typically cover costs directly related to the study, such as the investigational drug or device. Under the Affordable Care Act, most commercial plans must cover routine patient care costs associated with participating in an approved clinical trial. Medicare and Medicaid have parallel requirements for routine clinical trial costs.
However, patients usually remain responsible for deductibles, copays, and coinsurance on routine services, and many plans do not require out-of-network coverage. That can leave participants liable for costs if the trial site is outside their network.
Beyond medical expenses, incidental costs—travel, parking, lodging, childcare, and lost wages—can make participation financially infeasible. Some sponsors provide support for these expenses but do not always disclose that assistance up front. Patient advocates recommend asking trial teams about any available reimbursements or supports before enrolling.
Federal and advocacy actions aim to reduce barriers. The Department of Health and Human Services launched an initiative to streamline clinical research and requested input on modifying rules that currently limit sponsors from paying participant expenses such as travel and lodging. Advocacy coalitions have urged passage of the Clinical Trial Modernization Act, which would permit sponsors to cover medical and nonmedical participant costs and would exclude certain financial support from federal taxes to protect eligibility for income-based programs.
Despite these steps, implementation and widespread changes to trial access are still evolving. Decentralization, clearer sponsor reimbursement practices, and stronger referral pathways from clinicians are among the system changes that could broaden participation.
Search public registries such as clinicaltrials.gov and use disease-specific matching services from advocacy organizations.
Ask your treating facility whether trials are open onsite and request the contact information for trial recruiters.
Contact trial teams directly to confirm whether you meet eligibility criteria and whether the trial is still enrolling.
Check with your insurer about coverage for routine trial-related care, including network limitations, and confirm what out-of-pocket costs you might owe (deductibles, copays, coinsurance).
Ask whether the trial sponsor provides reimbursements for incidental expenses and whether financial support could affect eligibility for programs like Medicaid; advocates note sponsors sometimes offer help but do not always advertise it.
Consider whether decentralized trial options exist that could reduce travel or enable some procedures locally.
Being proactive—asking clear questions about eligibility, coverage, logistics, and available supports—can help patients weigh whether a clinical trial is feasible and worthwhile for them.