Participant Support Costs are defined by NSF as direct cost for items such as stipends or subsistence allowances, travel allowances, and registration fees paid to or on behalf of participants or trainees (but not employees) in connection with meetings, conferences, symposia or training projects.
At USC, we have separate class codes for stipends, travel, and registration fees, and another class code we call Participant (small item payments) Non-Reportable (54533).
The most common item USC has that falls within this class code is payment for interviews for participating in a particular program.
The best way to handle these payments is through the cash advance process.
[Cash Advance Process (Acrobat Reader - PDF)] 
DOWNLOADS:
[Cash Advance/Gift Card Form (Acrobat Reader - PDF)]
[free Adobe Acrobat Reader software to read PDF forms] 
If a participant cannot be paid in cash (one example would be the payment for an Interview done by telephone) then a DEV must be done. When the DEV is prepared the department should ensure that the "Description" states that the DEV is for Participant Support for the time period involved and reflect the name of the grant. Also, please make sure that there is a copy of the page from the grant attached which references such payments. Checks must be made payable to the participant with the participant's mailing address. NO PO BOXES. The Principal Investigator on the grant must approve DEV's. The checks will be mailed directly to the participant.
