Clinical trial payments: Which method is right for your study?
By Abby Quillen●7 min. read●Oct 14, 2026
Imagine taking time off work, traveling to a clinical trial site, and paying out of pocket for transportation, a hotel, and parking. After completing your visit, you have to wait weeks to be reimbursed for those expenses.
For many participants, this scenario is a reality. In one study, nearly two-thirds of oncology clinical trial participants reported financial stress related to participation. Many had to tap into savings, use credit cards, or reduce spending in other areas.
Clinical trial payments that are fast and accessible can ease some of that burden and help keep participants enrolled. The payment method you choose affects how quickly participants receive funds, how easily they can use them, and how much administrative work falls on your team. This makes it an important study design decision to consider early in the planning process.
This guide compares common clinical trial payment methods, outlines their advantages and limitations, and offers questions to help you choose the right one for your study.
Key takeaways
Payment method matters. How you pay clinical trial participants can influence enrollment, retention, and research staff workload.
Each method has different tradeoffs. Checks, physical prepaid cards, ACH transfers, digital payments, and cash vary in speed, accessibility, cost, and ease of administration.
You don’t have to choose just one. Offering multiple payment methods or using a payout platform can help accommodate different participant needs.
Clinical trial compensation is generally taxable in the U.S. Track each participant’s payments throughout the year so you know who reaches the IRS reporting threshold.
Why payment method affects clinical study outcomes
The payment method you choose can create barriers for participants and additional work for your team. Here’s how:
Enrollment diversity: Many research teams want their participant pool to be representative of the populations they’re studying. But some payment methods can work against that goal. For example, methods that require a bank account exclude people who don’t have one. As of 2023, 4.2% of U.S. households were unbanked. Other requirements, such as a reliable mailing address or access to a smartphone, also create barriers.
Retention: Financial burdens like time off work, travel, and lodging can lead some participants to drop out of a study. Delayed reimbursements add to that burden by leaving people to cover these costs for longer.
Timelines and site workload: Manual payment processes eat time and create reconciliation work for research teams. In one study, 19% of sites reported financial management and payments as their top issue.
Payment decisions also have ethical implications. The U.S. Food and Drug Administration (FDA) generally considers participant payments acceptable, but says an institutional review board (IRB) should review the amount, method, and timing to make sure they don’t create coercion or undue influence.
Types of clinical trial participant payments
Clinical trial payments generally fall into three categories based on what participants are being paid for:
Reimbursement: Participants are paid back for expenses they take on because of the study. This can include lodging, childcare, mileage, parking, and transit. Many organizations ask participants to submit receipts or documentation.
Compensation for time and effort: Participants are paid for the time and effort the study requires, such as attending visits, undergoing procedures, and filling out questionnaires. Compensation is typically calculated per visit or per hour, and IRBs review the amount to make sure it doesn’t pressure people into participating.
Additional incentives or completion bonuses: These are extra payments on top of regular compensation that reward participants for meeting certain milestones or finishing the study. IRBs review them closely, since a large bonus could pressure someone to stay in a study they’d otherwise leave.
According to FDA guidance, participants should accrue compensation gradually as a study progresses, and payment shouldn’t depend entirely on completing the study. A small completion bonus may be acceptable if it doesn’t create undue influence.
Comparing clinical trial payment methods
| Method | Participant requirements | Delivery speed | Best for | Limitations |
|---|---|---|---|---|
| Checks | A mailing address and the ability to deposit or cash a check | Several days in the mail, plus time for funds to clear | Participants without digital access | Slow delivery, risk of lost mail, possible cashing fees |
| Physical prepaid cards | A mailing address or in-person visit | Same day to several days once issued and funded | Multi-visit studies with frequent per-visit payments | Expiration dates and inactivity or replacement fees |
| ACH and direct deposit | A bank account | Same day to 2 business days | Recurring or one-time payments to participants with bank accounts | Requires secure collection and handling of banking details |
| Digital payment options | Email or phone access | Minutes to same day, depending on the method and provider | Decentralized or hybrid trials | Requires digital access, plus possible account setup |
| Cash | An in-person visit | Immediate | Small, single-site studies | Manual tracking and reconciliation |
Common clinical trial payment methods
Here’s a closer look at each method.
Checks
Checks are familiar to most people, and they’re compatible with established institutional accounts payable processes. They can also be useful for participants without a bank account or digital access.
But checks have some downsides. They can take several days to arrive in the mail, plus additional time to clear. They carry a higher risk of fraud than electronic methods, and participants without bank accounts sometimes have to pay a fee to cash them.
For research sites, printing, mailing, tracking, and reissuing checks can add to your team’s workload.
Physical prepaid and reloadable cards
You can issue physical prepaid cards at enrollment or mail them to participants. Reloadable cards are particularly useful for multi-visit studies because funds can be added to the same card after each visit.
Participants don’t need a bank account to use most prepaid cards, but some cards require activation or identity verification. Depending on the provider, prepaid cards might also come with an expiration date and fees, such as inactivity, ATM, or replacement fees. Lost cards also create extra work for site staff, who have to cancel and reissue them.
ACH and direct deposit
Automated Clearing House (ACH) transfers, including direct deposit, move funds electronically between banks. They’re generally inexpensive to process and can be used for both one-time and recurring payments.
Payments usually take up to two business days to arrive. That timing works well for studies with predictable payment schedules, but it may be a drawback for participants who need faster reimbursement.
ACH also requires participants to have a bank account, and your team will need a secure way to collect and store their banking details.
Digital payment options
This category includes digital wallets like PayPal and Venmo, virtual gift cards, and virtual prepaid cards. They’re quick to send, are often available within minutes, and there’s nothing to mail. That makes them a natural fit for decentralized or hybrid trials.
A payout platform that allows participants to choose their digital reward can be especially useful for studies with broad populations, since payout preferences vary. One person might prefer a PayPal transfer, while another wants a gift card for their local grocery store.
Digital options do have limits. Participants need reliable email or phone access, and some methods require creating an account. That can be a hurdle for people who are less comfortable with technology or reluctant to share personal information. Some research institutions, sponsors, and IRBs also restrict gift cards, so you’ll want to check their policies before choosing them as a payment method.
Cash
Cash is simple for participants because they’re paid on the spot and don’t need an account, card, or device to access their funds. It can work well for small, single-site studies where visits happen in person.
For sites, cash requires secure storage, manual tracking, and documentation of every payment, since there’s no automatic transaction record. That overhead makes it harder to manage at scale and a less practical option for decentralized or multi-site studies.
Choosing the right payment method for your study
The best payment method depends on who your participants are, how your study is structured, and what your institution allows. These questions can help guide your decision.
What can participants access and use? Consider whether your participants have access to bank accounts, a mailing address, email, smartphones, and reliable internet. Payment instructions should be available in participants’ preferred languages.
When and how often will payments be needed? Map out how many visits participants will attend, when they should be paid, and how quickly they need reimbursement. If you need to make frequent payments, account for the full time from approval to usable funds, plus the staff time required.
What participant information will you need? Determine what personal or financial information you’ll need to collect, how you’ll protect and store it, and whether participants will be comfortable sharing it.
Where will payments be delivered? Site-based, remote, and hybrid studies have different needs. For multi-site or international studies, confirm that a method works consistently across sites and is available in participants’ countries and local currencies.
What restrictions apply? Check institutional, IRB, sponsor, and tax requirements. Factor in any consent disclosures, permitted payment methods, and data-handling rules.
Who will manage payments? Clarify whether the sponsor, contract research organization (CRO), or site handles approvals, disbursement, participant support, recordkeeping, and tax reporting.
What’s the total cost? Account for platform and transaction fees, participant fees, currency conversion, and the staff time needed to administer payments.
Remember, you don’t have to pick just one payment option. Many studies offer multiple options to accommodate different participant needs.
Tax and compliance considerations
In the U.S., clinical trial compensation is generally treated as taxable income regardless of payment method. For payments made in 2026, sponsors or sites may be required to issue a Form 1099-MISC to anyone who reaches the $2,000 IRS reporting threshold within a calendar year. The tax treatment of documented expense reimbursements depends on the circumstances, so consult a tax advisor to determine whether they’re reportable.
If participants are likely to meet the threshold, it’s a good idea to collect W-9s at enrollment and store them securely. Gathering tax information up front is much easier than tracking it down come tax season. Payment methods that create a digital record, like ACH and digital options, also make reporting and auditing easier than cash or paper checks.
Payment amounts, methods, and timing are typically disclosed in the informed consent form and reviewed by the IRB. Changes to approved payment terms may require additional IRB review and approval.
International tax rules vary by country, so consult local counsel if you’re running a global trial.
Disclaimer: Tremendous can't provide tax or legal advice. While we've covered the basics of taxes and compliance here, you should run your clinical payment plans past your company's tax advisors to be sure you’re distributing payments in a way that’s fully compliant and optimized for your situation.
What to look for in a clinical trial payment solution
Digital payout platforms help research teams deliver funds quickly while simplifying payment management. They can also work alongside a fallback like checks or cash for people without digital access. If you’re evaluating clinical trial payment solutions, ask three questions:
Does it work for all of your participants? Look for a platform that lets participants choose how they receive funds, offers locally relevant options, and doesn’t charge them fees.
Does it reduce work for your team? Automated payments through an API or direct integrations with your existing systems can cut manual steps, and built-in reporting simplifies reconciliation.
Does it support compliance? Prioritize features such as secure data handling, tax form collection, and fraud prevention.
Think back to the participant waiting weeks for reimbursement. The right solution can shorten the wait while keeping the process manageable for your team.
