Not all IRBs and research institutions specifically address limits to how much researchers can compensate study participants.

But allowing these limits to default to what is reportable to the IRS as income could be a mistake, one IRB chair says.

“We did a survey and found that only 10% of research institutions actually had a policy about incentive payments,” says Michelle DuBois, PhD, associate IRB chair and associate professor of biology at Seattle University.

“Some institutions did not allow any incentive payments, but those were few and far between,” she adds. “When we went through research online, we found that limits ranged widely.”

Allowing researchers to offer some kind of payment for participation in a study is extremely reasonable, DuBois says.

“Some people argue for larger incentive payments for some studies,” she adds. “It really comes down to what kind of study is being done and what kind of population is involved.”

Studies mainly encourage someone to participate under the theory that the participant’s time is worth compensating.

“Is there a reason why someone should give two hours for an interview when they don’t have to?” DuBois says. “Is it worth $20 for their time? Is it worth $50? Those are the kinds of questions researchers come up against.”

Other incentive questions involve how incentives should be provided. Should they be in cash, gift cards, or products? A $10 T-shirt also is an incentive, and transportation passes or tokens are incentive payments even if they are used to reimburse participants for travel to the research site, DuBois says.

And everything that is an incentive payment, whichever form it takes, counts toward an institution’s incentive limit.

IRBs also should learn more about their state’s laws when an incentive payment involves a drawing or raffle. There generally is a $600 threshold for reporting the winning prize to the IRS. (More information on reporting is available at:

Research institutions often default to the $600 threshold, DuBois notes.

“They say, ‘We don’t have a limit in terms of reporting, but the IRS does, and as a result, that is what we have for our policy,’” she says.

But there also could be state laws that prohibit raffles, DuBois says.

“That’s something for IRBs to note: Make sure the incentives aren’t breaking state laws if they are lotteries, raffles, or drawings,” she says.

Incentive payments also count toward the IRS reporting threshold of $600 in payments to individuals. What this means is that anytime an institution pays someone $600 or more, the institution must obtain the person’s Social Security number (SSN) and file IRS form 1099-MISC. (For more information, visit:

Asking research participants for their SSNs can be awkward, which is partially why it is very unusual for research participation incentives to exceed the $600 limit. Individual institutions can make their own policies more stringent. For instance, Seattle University offers a $50 incentive payment limit before the investigator has to ask for participants’ SSNs.

“In terms of minimal-risk projects, researchers need to talk with people and maintain privacy,” DuBois says. “If you report Social Security numbers, people are less inclined to participate.”

Seattle University reached its $50 limit after trial and error and collecting data on incentive payments.

For a while, the university allowed no incentive payments. That policy was unpopular, so the institution enacted a $25 maximum payment without disclosure of an SSN, she explains.

After reviewing incentive payment policies at other institutions, they decided to double the limit to $50.

“We coordinated with our controller’s office and the office of sponsored projects to come up with our limit of $50, which is the trigger amount at which a Social Security number needs to be reported,” DuBois says.

The $50 trigger would apply to any collective payments to a single research participant. For example, if a participant is given $10 bus ride cards to reimburse for travel each time he or she visits the clinic, then the fifth visit would amount to $50, the payment limit before an SSN is collected.

“If it’s over $50, it needs to be reported to the controller’s office,” DuBois says. “At Seattle University, we primarily have minimal-risk protocols, and these are not the kinds of studies that would merit hundreds of dollars in payment for participation.”

The institution tries to balance what seems reasonable with regard to the payment, study, and population being targeted, she explains.

“We encourage researchers working with various types of vulnerable populations to take into consideration how those types of environments might impact participants receiving an incentive payment,” DuBois says. “Those types of considerations are the ones the IRB examines for each protocol.”