Limited Competition: Small Grant Program for NHLBI K01/K08/K23/K25 Recipients (R03 Clinical Trial Optional) | RFA HL 27 004

Opportunity Information: Apply for RFA HL 27 004

The Limited Competition: Small Grant Program for NHLBI K01/K08/K23/K25 Recipients (R03 Clinical Trial Optional) (RFA-HL-27-004) is a National Institutes of Health funding opportunity from the National Heart, Lung, and Blood Institute (NHLBI) designed to help certain career development (K) awardees take a concrete step toward research independence. It uses the NIH R03 small grant mechanism to provide short-term, targeted support for projects that either extend the investigator's current K award research aims or launch a closely connected new line of inquiry that grows out of the K award work. The overall idea is to help K awardees generate the kind of preliminary data and project momentum that can strengthen a later R01-equivalent application, which is often the key next milestone in an investigator's transition to an independent research program.

This opportunity is intentionally narrow in who can apply. It is a limited competition specifically for current or recently completed NHLBI K01, K08, K23, and K25 award recipients. Current K awardees can apply beginning in the third year of their K award project period, which aligns with the point when many investigators have enough early results to justify a well-scoped, add-on pilot study. Investigators who have already finished their NHLBI K award can also apply (or submit a resubmission, A1) as long as the earliest possible start date for the R03 would fall within two years after the end of their K award project period. This timing window is meant to keep the R03 tightly linked to the K award trajectory and to support continuity as the investigator moves toward larger independent funding.

The R03 mechanism itself is built for smaller projects that can be completed within two years using limited resources, and the NOFO lists several examples of the kinds of studies that fit well. These include pilot and feasibility studies, proof-of-concept work, secondary analyses of existing datasets, small self-contained research projects, development of new research methods or technologies, and creation of new experimental model systems. In practice, the expectation is not that the R03 will fully answer a broad scientific question, but that it will produce compelling preliminary findings, refine an approach, test a key assumption, or generate critical tools or methods that make a subsequent larger grant application substantially more competitive.

A major requirement tied to the career development intent of this program is protected research time. During the R03 award period, applicants must maintain at least 40 percent protected research effort. Importantly, that 40 percent does not have to be charged only to the R03; it can be met through a combination of effort on the R03 and other research projects, regardless of where the other support comes from. The point is that awardees must be able to show they will continue to have meaningful, dedicated time to do research while they complete the R03 work and prepare for the next stage of independent funding.

The NOFO is labeled "Clinical Trial Optional," meaning applicants may propose studies that include a clinical trial if it is appropriate for the scientific goals, but a clinical trial is not required. The announcement also clarifies a common question for K23 investigators: for current and former K23 awardees, the R03 project may include patient-oriented research, but it does not have to. That flexibility allows K23 recipients to either deepen patient-oriented work or pivot toward other research components that logically emerge from their K23 foundation, such as mechanistic studies, methods development, analytics, or model development, depending on the investigator's trajectory.

Eligibility rules also include clear limits on foreign involvement. Non-U.S. (foreign) organizations are not eligible to apply. In addition, non-U.S. components of U.S. organizations are not eligible, and foreign components (as defined by NIH policy) are not allowed under this opportunity. In other words, the work and the participating organizational components must be domestic under NIH definitions for this specific NOFO.

From an administrative and funding standpoint, this is a discretionary NIH grant opportunity that will be reviewed through standard NIH peer-review procedures, and only applications judged meritorious will be considered for funding. The opportunity lists an award ceiling of $85,000 and anticipates approximately 29 awards. The posted closing date is 2028-11-07. The broad set of eligible applicant organization types includes many standard NIH-eligible entities, such as institutions of higher education (public and private), nonprofits (including 501(c)(3) and non-501(c)(3)), for-profits (other than small businesses), small businesses, and various government and tribal entities. That said, the practical gatekeeper for this NOFO is not the organization type but the principal investigator's status as an eligible current or recently completed NHLBI K01/K08/K23/K25 awardee within the stated timing rules.

In plain terms, this program is a bridge: it gives NHLBI K awardees a small, time-limited pool of support to run a focused study that strengthens their scientific and funding trajectory. The best-fit applications are typically those that are tightly scoped for two years, clearly connected to the investigator's K award foundation, and explicitly framed around producing the preliminary data, methods, or proof-of-concept needed for a strong next-step R01-level proposal.

• The National Institutes of Health in the health sector is offering a public funding opportunity titled "Limited Competition: Small Grant Program for NHLBI K01/K08/K23/K25 Recipients (R03 Clinical Trial Optional)" and is now available to receive applicants.
• Interested and eligible applicants and submit their applications by referencing the CFDA number(s): 93.233, 93.837, 93.838, 93.839, 93.840.
• This funding opportunity was created on 2026-05-12.
• Applicants must submit their applications by 2028-11-07.
• Each selected applicant is eligible to receive up to $85,000.00 in funding.
• The number of recipients for this funding is limited to 29 candidate(s).
• 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 RFA HL 27 004

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