Participant Support Costs: What Qualifies (NSF)

Last verified: August 16, 2026. Participant support costs are one of the few federal budget categories that behaves nothing like the direct costs around it. They get their own line on the budget form, they are walled off from a grantee’s indirect-cost (F&A) rate, and moving money out of the category generally requires the funding agency’s written permission before you spend it — not after. This page covers what the category actually includes, why the exclusion exists, and where the rebudgeting restriction comes from, using NSF’s treatment as the primary worked example.

Quick answer

Question	Answer
What is it?	Direct costs paid to or on behalf of non-employee participants in a federally funded conference, symposium, or training activity — not payments to project staff.
Where is it defined?	2 CFR 200.1 (the Uniform Guidance definitions section; the definition previously lived at the now-superseded 2 CFR 200.75 before OMB’s 2020 recodification folded the numbered definitions into 200.1).
What counts?	Stipends, subsistence/per-diem allowances, travel allowances, registration fees, and temporary dependent care paid directly to or on behalf of participants.
Does F&A apply?	No. Participant support costs are excluded from the Modified Total Direct Cost (MTDC) base, so a grantee’s negotiated indirect-cost rate cannot be applied to them.
Can you move the money elsewhere?	Not without prior written agency approval. Rebudgeting funds out of the participant support cost category is one of the specific actions 2 CFR 200.308 flags as requiring sign-off before the transfer, regardless of the award’s general rebudgeting threshold.

What qualifies as a participant support cost

Per 2 CFR 200.1, participant support costs are direct costs that support participants and their involvement in a federal award, specifically:

Stipends paid to participants (not compensation to project staff or employees)
Subsistence allowances and per diem paid directly to or on behalf of participants
Travel allowances to bring participants to and from the activity
Registration fees for the conference, symposium, or training event
Temporary dependent-care costs that allow a participant to attend

The category exists specifically for meetings, conferences, symposia, and training-type activities where the award is bringing in outside participants — students, trainees, or other non-employees — rather than paying the institution’s own research staff to do the work. NSF’s Proposal & Award Policies and Procedures Guide (PAPPG) requires participant support costs to be budgeted and reported as their own distinct line item, separate from other direct cost categories such as travel, participant-unrelated stipends, or materials and supplies — they cannot be folded into a general travel or personnel line.

What does NOT qualify

Salary or wages paid to the institution’s own employees working on the project — that is personnel compensation, a different budget category entirely.
Travel or per diem for the PI or project staff to attend a conference to present findings — that is ordinary project travel, not participant support.
Subawards or contracts for services rendered — participant support is a payment to a participant for attending, not payment for a deliverable.
Costs for a training activity that is not part of the funded project’s approved scope — the activity itself has to be identified and justified in the proposal/award.

Why participant support costs are excluded from MTDC

Modified Total Direct Cost (MTDC) is the base an institution’s negotiated indirect-cost (F&A) rate is applied against. 2 CFR 200.1 lists participant support costs among the specific categories excluded from that base, alongside items like equipment, capital expenditures, the portion of each subaward beyond a set threshold, and tuition remission. See our MTDC (Modified Total Direct Cost) glossary entry for the full exclusion list and how the base is calculated.

The practical effect: an institution cannot charge its indirect-cost rate against the stipends, travel, and fees paid to participants. If a project budgets $50,000 in participant support costs, that $50,000 generates no F&A recovery for the institution — it passes through to participants (or their travel/lodging/registration providers) without an indirect-cost markup layered on top. This is a deliberate policy choice: participant support costs are treated as a pass-through benefit to the people the training or conference is meant to serve, not as institutional overhead-generating activity.

Why rebudgeting is restricted

Most direct-cost categories on a federal award can be moved around within a reasonable threshold (commonly a 10% MTDC/total-budget deviation rule) without needing the agency’s prior written approval. Participant support costs are a specific, named exception. 2 CFR 200.308 lists the transfer of funds budgeted for participant support costs to other budget categories among the actions that require prior approval from the federal awarding agency regardless of the size of the transfer or the award’s general rebudgeting authority.

Why the rule exists: the amount an institution proposes for participant support costs is part of what the funding agency evaluated and approved when it made the award — the number of trainees or conference attendees the project promised to support is effectively a term of the award. Quietly redirecting that money into other categories (equipment, additional staff time, supplies) would change what the award is actually funding without the agency having agreed to that change. The restriction runs one direction as a practical matter: moving money out of participant support costs is what triggers the prior-approval requirement; increasing the participant support budget from savings elsewhere is comparatively less contentious, but should still be confirmed against the specific award’s terms and the agency’s current PAPPG/Grants Policy Statement before assuming it is automatic.

For the full list of budget actions that trigger prior approval government-wide, see our guide to federal grant prior approval, rebudgeting, and cost allowability and the prior approval glossary entry.

Unspent participant support funds

Because the category is tied to a specific, agency-approved activity rather than general project support, unspent participant support balances are treated differently from ordinary cost savings at closeout. Many agencies, including NSF, do not allow unused participant support funds to be freely repurposed for other project costs at the end of the award; check the specific award’s terms and the current PAPPG or agency grants policy statement, since practice on this point varies by agency and by award type and is not uniform across every federal funder.

Where participant support costs show up on the budget form

On NSF’s budget form, participant support costs appear as their own line (Line G), separate from Senior Personnel, Other Personnel, Fringe Benefits, Travel, and Other Direct Costs. Any indirect-cost calculation on the same form excludes that line from the base, consistent with the MTDC exclusion above. See our worked example in budget justification: a worked example and the general walkthrough in how to build a research budget for how the category fits alongside other direct-cost lines.

Frequently asked questions

Is “participant support costs” the same as 2 CFR 200.75?

200.75 was the section number that held this definition before OMB’s 2020 recodification of the Uniform Guidance. The definition itself now lives at 2 CFR 200.1, alongside every other defined term in the regulation. The substance of the definition has not materially changed; only its location in the numbering has.

Can indirect costs (F&A) be charged on participant support costs?

No. Participant support costs are specifically excluded from the Modified Total Direct Cost base that an institution’s negotiated F&A rate is applied against. See how to calculate indirect costs and 2 CFR 200 Subpart E cost principles for how the MTDC base is built and what else is excluded from it.

Do I need prior approval to move money out of participant support costs?

Yes, as a general federal rule under 2 CFR 200.308 — this applies regardless of your award’s ordinary rebudgeting threshold. Confirm the specific process with your program officer and grants management specialist, since the mechanics of requesting the change (and any agency-specific dollar thresholds layered on top of the government-wide rule) vary by funder.

Does the participant support cost category apply to every type of federal award?

The category is most relevant to awards that include a conference, symposium, or training component with non-employee participants — common in NSF conference and training grants, and in awards under agencies that fund workshops, institutes, or similar convening activities. Not every award includes a participant support cost line; whether it applies depends on the nature of the funded activity, not the agency alone.

Participant Support Costs: What Qualifies and Why It Matters

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