Ancillary Studies to Ongoing Clinical Projects (R21 Clinical Trial Not Allowed) | PAR 25 230

Opportunity Information: Apply for PAR 25 230

The National Institutes of Health (NIH) is offering a discretionary grant opportunity titled "Ancillary Studies to Ongoing Clinical Projects (R21 Clinical Trial Not Allowed)" under funding opportunity number PAR-25-230 (CFDA 93.846). This program supports short, exploratory ancillary studies that build on, leverage, or add value to clinical research projects that are already underway. The mechanism is an R21, which is typically used for early-stage, proof-of-concept, or high-impact exploratory work rather than large, fully mature research programs. A key limitation is stated directly in the title: clinical trials are not allowed under this announcement, meaning applicants must propose research that does not meet NIH's definition of a clinical trial (for example, not prospectively assigning human participants to interventions to evaluate effects on health-related outcomes). The intent is to encourage efficient, targeted add-on studies that can answer important additional questions using the infrastructure, cohorts, specimens, data streams, or operational platform of an existing clinical project, without turning the ancillary work into a new intervention trial.

This announcement is a re-issue of PAR-23-026 and was re-issued specifically due to NIH's "Simplifying Review of Research Project Grant Applications" initiative. Practically, that means the substantive scientific purpose, eligibility expectations, and overall program structure are described as unchanged, while the peer review language and criteria in Section V have been updated to align with NIH's simplified review framework. In other words, the main update is about how applications will be evaluated during peer review (the review format/criteria), not about what types of studies NIH wants, who can apply (aside from the clarifications provided), or what the grant is intended to fund.

The funding instrument is a grant, and the award ceiling listed is $250,000. The source information provided does not specify the number of expected awards. The original closing date shown is 2025-12-05. Because the activity category is "Health" and the administering agency is NIH, applicants should expect standard NIH application requirements, including alignment with NIH policies, budgeting rules, and human subjects protections as applicable. Even though clinical trials are not allowed, many ancillary studies may still involve human data or biospecimens, so compliance with NIH human subjects rules, privacy protections, and data management expectations may still be relevant depending on the project design.

Eligibility is broad and includes many U.S.-based organization types across government, academia, nonprofit, and industry. Eligible applicants include state, county, and city or township governments; special district governments; independent school districts; public and state-controlled institutions of higher education; private institutions of higher education; Native American tribal governments that are federally recognized; public housing authorities/Indian housing authorities; Native American tribal organizations other than federally recognized tribal governments; nonprofits with 501(c)(3) status and nonprofits without 501(c)(3) status (in both cases, other than institutions of higher education); for-profit organizations other than small businesses; and small businesses. The announcement also explicitly highlights additional eligible applicant categories, including Alaska Native and Native Hawaiian Serving Institutions, Asian American Native American Pacific Islander Serving Institutions (AANAPISIs), faith-based or community-based organizations, Hispanic-serving institutions, Historically Black Colleges and Universities (HBCUs), Tribally Controlled Colleges and Universities (TCCUs), eligible agencies of the federal government, regional organizations, and U.S. territories or possessions.

At the same time, the announcement includes a clear restriction regarding foreign involvement. Non-domestic (non-U.S.) entities (foreign organizations) are not eligible to apply, and non-domestic (non-U.S.) components of U.S. organizations are also not eligible to apply under this opportunity. That means the applicant organization must be domestic, and the project components supported by this grant must not be carried out through a non-U.S. component of a U.S. organization under this particular funding announcement. This restriction is important for teams that might otherwise plan to place work or subcomponents overseas, or for U.S. organizations that operate foreign branches or research sites.

Overall, PAR-25-230 is best read as NIH support for focused, add-on research questions that can be addressed efficiently by piggybacking on an ongoing clinical project, while keeping the proposed work in the non-clinical-trial space. The re-issue largely signals a modernization of the peer review approach (simplified review changes in Section V) rather than a shift in the scientific scope, budget limits, or eligibility structure, aside from the explicit reiteration of the domestic-only applicant and component restrictions.

• The National Institutes of Health in the health sector is offering a public funding opportunity titled "Ancillary Studies to Ongoing Clinical Projects (R21 Clinical Trial Not Allowed)" and is now available to receive applicants.
• Interested and eligible applicants and submit their applications by referencing the CFDA number(s): 93.846.
• This funding opportunity was created on 2024-12-09.
• Applicants must submit their applications by 2025-12-05. (Agency may still review applications by suitable applicants for the remaining/unused allocated funding in 2026.)
• Each selected applicant is eligible to receive up to $250,000.00 in funding.
• Eligible applicants include: State governments, County governments, City or township governments, Special district governments, Independent school districts, Public and State controlled institutions of higher education, Native American tribal governments (Federally recognized), Public housing authorities/Indian housing authorities, Native American tribal organizations (other than Federally recognized tribal governments), Nonprofits having a 501 (c) (3) status with the IRS, other than institutions of higher education, Nonprofits that do not have a 501 (c) (3) status with the IRS, other than institutions of higher education, Private institutions of higher education, For-profit organizations other than small businesses, Small businesses, Others.

Apply for PAR 25 230

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