Payment Considerations

Overview

Federal regulations require that “An investigator shall seek such consent only under circumstances that provide the prospective subject or the representative sufficient opportunity to consider whether or not to participate and that minimize the possibility of coercion or undue influence.” (45 CFR 46.116(a)(2); 21 CFR 50.20). For additional information on research with drugs or devices, see also the FDA guidance on Payment and Reimbursement to Research Subjects.

While no clear line distinguishes between proper and unreasonable payments and what may be excessive in one situation may not be in another, payment amounts should be reasonably commensurate with the time and effort required of the participants in the study. Undue influence occurs “through an offer of an excessive, unwarranted, inappropriate or improper reward or other overture” (Belmont Report).

Paying research participants for their participation is a common and, in general, acceptable practice. Payment for research participation should be just and fair and should not be promoted as a way of offsetting risks, meaning it should not be considered a benefit to be weighed against the study risks. The level of payment should not be so high as to cause a prospective participant to accept risks that he or she would not accept in absence of payment.

Considerations for IRB Applications

Protocols submitted to the IRB should indicate and justify proposed levels and purposes of payment, pursuant to the following four categories:

• Reimbursement for direct expenses (e.g. actual costs for parking, meals, lodging and transportation). If the amount a participant will be reimbursed is limited, include this information in the consent form.
• Compensation for time and inconvenience (e.g. payment in an hourly amount for all or some of the hours required of the research participant that represents time away from work).
• Appreciation payments at token levels or token gifts (e.g. movie coupons, toys, gift certificates – amounts under $25.)
• Incentive payments (designed to act as incentives and are in amounts above the participant’s actual costs incurred and above token levels.)

In general, reimbursement for direct expenses, compensation for time and inconvenience in reasonable amounts and token gifts are usually justifiable and acceptable forms of payment. It is when proposed payment amounts are not reasonably related to the time and effort required of participants that financial considerations may become a coercive factor or unduly influence a participant’s decision to participate in research. To avoid unduly influencing decisions about research participation, incentive payments should be in reasonable amounts.

In research with considerable duration or that involves multiple interactions or interventions, payments should be prorated over the course of the study, rather than holding payment until study completion. Conditioning payment on completing the study could unduly influence a participant’s decision to exercise his or her right to withdraw at any time.

Research with Children

When children are research participants, consider whether the payment will be made to the parent(s) or the child, or both. If the child is paid, be aware of the different ways children of varying ages view the value of a payment and ensure the payment is age appropriate. 

Payment Processing Requirements

Investigators have fiduciary responsibility to account for funds spent in study. Researchers should be aware that payments to research participants may be considered taxable income to study participants and that payment processing options differ depending on the payment amount, method, and payee type. If it is necessary to obtain sensitive information (e.g., SSN) for payment purposes, participants should be informed of those requirements so they can make an informed decision about participating in the research. For more information on payment processing requirements, please see the Stanford Gateway to Financial Activities: Paying Human Subjects webpage.

Raffles/Drawings

If the study will offer a raffle/drawing such as for a gift card or cash, the study’s planned payment scheme is considered by Cal. Bus. & Prof. Code § 25600.2 to be a “sweepstakes” (see below definitions).

• Sweepstakes – A winner is chosen at random from a list of all participants. The number of participants determines the odds of winning.
• Contest – A judge decides a winner based on participants’ skill or other criteria.
• Lottery – A winner chosen at random from a list of all participants. Participants are required to pay to enter the lottery. The number of participants determines the odds of winning.

This payment scheme must allow anyone to enter your drawing, even if they do not participate in the research study (e.g., if they do not start enrollment or complete the study task). The recruitment materials and the consent form must state that anyone is eligible to enter the drawing by contacting the study team. The recruitment materials and consent form must also include the date the winner(s) will be announced, and the odds of winning each prize. Avoid use of the word “lottery” as California defines it narrowly requiring participants to pay to enter and prohibits use of lotteries except for the state and charitable organizations (e.g., bingo).

Page updated February, 2026