Clinical trial participant payments are any money or value a participant receives for taking part: reimbursement for parking, mileage and lodging, compensation for time, and sometimes a bonus for finishing. FDA allows them, provided payment accrues as the study goes on rather than depending on completion, any completion bonus is small, and the amount and schedule are written into the consent form and reviewed by the IRB. Two things changed this year for the site that hands the money out. In June 2026 HHS's Office of Inspector General asked whether participant payments need a new anti-kickback safe harbor, because none exists. And from 2026 the IRS reports research payments on Form 1099-MISC only at $2,000 or more, not $600.
In short
- FDA: payment is "a recruitment incentive," not a benefit, and should accrue as the study progresses, with only a small proportion tied to completion (FDA, 2018).
- OIG has issued 10 favorable advisory opinions in two decades on cost-sharing for trial participants, and none on transportation, childcare or stipends (OIG, 2026).
- The anti-kickback statute is a felony with fines up to $100,000 and up to 10 years in prison (OIG RFI, 2026).
- Research participation payments go in box 3 of Form 1099-MISC at $2,000 or more for 2026 (IRS, 2026).
Why participant payments go wrong at a site
The sponsor designs the payment schedule and funds it. The site is the one that explains it at consent, pays it visit by visit, answers the phone when a card does not load, and keeps the paper. When something goes wrong, it goes wrong at the site.
The usual failures are small and specific. A participant is told "you get paid when you finish" when the consent says per visit. A reimbursement is paid without a receipt. A stipend schedule changes in an amendment and the old amounts keep going out. A participant crosses a tax threshold and nobody has their taxpayer identification number. None of these is fraud. All of them are findings.
FDA's guidance sets the frame. "Payment to research subjects for participation in studies is not considered a benefit," it says; "it is a recruitment incentive." That is why the IRB looks at it at all: the question is whether the amount, or the way it is paid, could push someone to enrol or stay when they otherwise would not.
What FDA's guidance requires
FDA's 2018 guidance, still the reference for FDA-regulated trials, comes down to five points:
| Point | What the guidance says |
|---|---|
| Timing | Credit for payment "should accrue as the study progresses" |
| Completion bonus | "A small proportion" is acceptable if not coercive |
| Travel | Travel, airfare, parking and lodging do not raise undue influence concerns |
| Consent | Amount and schedule "should be set forth in the informed consent document" |
| IRB | Reviews the amount and the method and timing of disbursement |
None of this is new. What is new is that the anti-kickback question, which sat in the background for years, is now on the record.
What the OIG asked in June 2026
On June 24, 2026, as part of HHS's Operation TrialBlazer, the Office of Inspector General published a request for information (file code OIG-2602-N) on remuneration to clinical trial participants. Its starting point is blunt. OIG has "published 10 favorable advisory opinions over the last 2 decades" allowing the waiver or subsidy of federal health care program cost-sharing for trial participants in specified trials, given by manufacturers, sites and non-profits. It has "not issued any advisory opinions or guidance relating to other remuneration provided to clinical trial participants, such as transportation costs, childcare costs, or stipends."
The statute it is asking about is serious. The anti-kickback statute is a felony "punishable by fines of up to $100,000 and imprisonment for up to 10 years," and the beneficiary inducements penalty separately reaches remuneration to Medicare and Medicaid beneficiaries that is likely to influence their choice of provider.
The fourteen questions are close to a site's daily work: which categories of payment actually help enrolment, whether trials cap payments or require receipts, who is allowed to pay (sponsor, investigator, other providers), whether the IRB's review is a real safeguard, whether advertising of payment should be limited, and how to stop a paid participant being steered to the payer's services outside the trial. Comments were due August 24, 2026, as Hall Render's summary of the initiative records. A request for information is not a rule; any safe harbor would come first as a proposal.
How a site should handle clinical trial participant payments now
- Match every payment to the approved consent. Build the site's payment log from the consent's schedule: visit, amount, type (reimbursement, compensation, completion). If a payment is not on the schedule, it does not go out until the sponsor and IRB say so.
- Pay as the study progresses. Per visit, or in instalments, never all at the end. Keep any completion payment small, as FDA's guidance requires, and keep it labelled as such.
- Keep reimbursement and compensation apart. Reimbursement is for costs the participant actually incurred, with a receipt or a documented rate. Compensation is for time and burden. Mixing them is how a "reimbursement" becomes an inducement on paper.
- Know which participants are Medicare or Medicaid enrollees. The beneficiary inducements penalty is limited to those programs. For those participants, ask the sponsor in writing who provides the payment, on what basis, and whether any cost-sharing waiver relies on an OIG advisory opinion.
- Track each participant's calendar-year total against $2,000. The IRS instructions list "a payment or series of payments made to individuals for participating in a medical research study" in box 3 of Form 1099-MISC. Collect the taxpayer identification number at enrolment, before the total gets close. Our service business post on the 1099 threshold change covers the same $2,000 line from an employer's side.
- Update the schedule the day an amendment is approved. A new visit, a new procedure or a longer stay usually changes the payment table. Apply it from the IRB approval date, not from the next monitoring visit.
- Explain the schedule in words a participant can repeat back. The consent should say when they get paid, how, and what happens if they withdraw. Most payment calls are a participant checking that the site remembers what it promised.
The mistake most sites make at step 4
They treat the anti-kickback question as the sponsor's problem. The sponsor writes the policy, but the site hands over the card, waives the copay or books the ride. OIG's question 5 asks precisely "who is eligible to provide remuneration," naming sponsors, investigators and other providers. A site that cannot show where each payment came from, and that it matched the approved schedule, has nothing to point to if the question is ever asked.
Where this fits
Payments are part of keeping people in a study; the visit itself is the rest of it. We wrote about the missed visit as the first retention signal and about measuring site burden before a sponsor asks. Our clinical research work includes an assistant that reads the site's protocols, consents and amendments and answers with the document and section cited, so the coordinator's answer to "what am I owed" is the approved one. It reads documents only; it does not issue payments or decide what is permitted.
Pull the current consent for each active study this week and check that the payment log matches it, visit by visit.
