Some clinical trials pay participants for their time and reimburse costs such as travel, parking or meals. Many do not. Whether compensation is available, how much it is and how it is paid depends on the study, and it is always described in the consent form before you agree to take part.
Payment versus reimbursement
Studies may offer two different things. Reimbursement covers out-of-pocket costs of taking part, such as mileage or lodging. Payment compensates you for your time and inconvenience. The FDA does not consider reasonable reimbursement for travel and lodging to raise concerns about undue influence (FDA: Payment and Reimbursement to Research Subjects).
How FDA guidance shapes payment
The same FDA guidance sets out how ethics boards (IRBs) should review payment:
- Payment is a recruitment incentive, not a benefit of the research, so it cannot offset study risks.
- The IRB reviews the amount, method and timing of payment to make sure it is not coercive.
- Payment should build up as the study goes on rather than depend on finishing the whole study. A small bonus for completion can be acceptable.
- The full amount and schedule of payments should appear in the consent document.
What research shows about payment levels
Published data on payment are limited, and most comes from Phase 1 studies in healthy volunteers, which often involve overnight stays. A 2021 study in the journal Clinical Trials analyzed 1,001 US Phase 1 trials that healthy volunteers screened for. It found a median total payment of $3,070 per trial, ranging from $150 to $13,000, and a median of $196 per study day (Fisher et al., 2021, PMC8290991). Those figures do not describe studies for people with a condition, which may offer less, only reimbursement or nothing at all.
Costs and insurance
The study sponsor usually pays for the investigational product and study-specific tests. Routine care you would receive anyway may be billed to your insurance. Medicare covers routine costs of qualifying clinical trials (CMS National Coverage Determination 310.1), and the Affordable Care Act requires most non-grandfathered private plans to cover routine patient costs for people in approved clinical trials. Ask the study team which costs are covered before you enroll.
Taxes
Payments for taking part in research are generally treated as taxable income in the United States, and study sites may issue a tax form. Reimbursement of documented expenses is handled differently. Ask the study team how payments will be reported, and check with a tax professional if you are unsure.
Questions to ask about compensation
- Is there payment for time, reimbursement for expenses, or both?
- How and when is it paid: per visit, at milestones or at the end?
- What happens to payment if I leave the study early?
- Which costs will be billed to my insurance, and which will the sponsor cover?
Compensation should never be the only reason to join a study. To understand what participation involves, read how clinical trials work.
Source: ClinicalTrials.gov, data processed . Recruiting US sites filtered by distance and site status; summaries shortened.