NIH R21 Grants — Exploratory/Developmental Grant
Reviewed by Dr. Meng ZhaoLast reviewed June 9, 2026Data refreshed June 9, 2026Editorial standards
Novel, high-risk/high-reward exploratory research
Funding
Up to $275,000 direct costs over 2 years (combined)
Duration
Up to 2 years
Eligibility
Any qualified investigator; preliminary data not required
Activity code
R21
What is the NIH R21 grant?
The R21 is the NIH Exploratory/Developmental Research Grant — designed for novel, high-risk/high-reward research where preliminary data may be limited or absent. The total budget is capped at $275,000 in direct costs over the entire grant (typically split as $150K + $125K, but flexibility exists), and the maximum project period is 2 years.
Recent R21 awards from NIH RePORTER
Examples of funded R21 projects across the last two fiscal years. The matching-award count comes from the full result set; funding totals, averages, rankings, and examples use the first 500 records returned by NIH RePORTER. Figures reflect a snapshot last refreshed on June 9, 2026.
Example R21 projects from the sample
Mechanisms of Axonopathy in CMT1X
1R21NS142944-01A1CHARLES ABRAMS · UNIVERSITY OF ILLINOIS AT CHICAGO, IL · $200,413 · awarded Jun 5, 2026 · NIHCharcot-Marie-Tooth disease (CMT) is the eponymous designation for inherited disorders characterized exclusively or predominantly by neuropathy. CMT affects approximately one in 2500 individuals worldwide. For the most part, mutations in genes expressed exclusively in Schwann cells, the myelinating cell of the PNS, produce demyelinating CMT. However,…
Multifaceted Immunomodulatory Self-Healing Glue for Treatment of Chronic Wounds
1R21AR083090-01A1Nasim Annabi · UNIVERSITY OF CALIFORNIA LOS ANGELES, CA · $368,156 · awarded Jun 5, 2026 · NIHProject Summary Chronic wound repair is a critical therapeutic need, particularly for wounds arising from mechanical trauma, burns, surgeries, or chronic conditions such as diabetes. Current wound dressings primarily provide physical protection but often lack the multifunctionality needed to support the body’s natural healing processes, especially in the…
Characterization of bicornuate cones in the human retina
1R21EY037882-01A1Vadim Arshavsky · DUKE UNIVERSITY, NC · $405,373 · awarded Jun 5, 2026 · NIHRod and cone photoreceptors are highly specialized cells responsible for transforming the information reaching the eyes in the form of photons into the language of neuronal activity. Human vision relies primarily on cones, which support high acuity color vision. It is commonly accepted that, like in all other placental mammals, human cones have a…
Engineered Treg therapy for pediatric Crohn's disease.
1R21TR005511-01A1Rosa Bacchetta · STANFORD UNIVERSITY, CA · $427,146 · awarded Jun 5, 2026 · NIHSummary Pediatric Crohn’s disease (CD) is a rare and chronic immune-mediated condition that is managed, but not cured, with continuous anti-inflammatory/immunosuppressive drugs. The condition leads to impaired growth, poor quality of life, and irreversible organ damage that often necessitates surgery, although surgery does not usually fully resolve or…
Use of scnn1b transgenic mice to develop new vaccines against pulmonary Mycobacterium avium
1R21AI193591-01A1Getahun Abate · SAINT LOUIS UNIVERSITY, MO · $423,500 · awarded Jun 3, 2026 · NIHOver the past fifteen years, there has been an increase in the prevalence of pulmonary nontuberculous mycobacteria (NTM) in the US and other developed countries. Patients with underlying lung diseases such as chronic obstructive lung disease (COPD) and cystic fibrosis (CF) are at increased risk of developing pulmonary NTM infections. Mycobacterium avium…
Modulation of efferocytosis in systemic sclerosis
1R21AR086493-01A1Sanja Arandjelovic · UNIVERSITY OF VIRGINIA, VA · $377,506 · awarded Jun 3, 2026 · NIHProject Abstract Systemic scleroderma (SSc) is an autoimmune disease that induces cutaneous, pulmonary, and abdominal organ fibrosis. In the most severe cases, SSc can lead to loss of organ function and death. Clearance of apoptotic cells, also known as ‘efferocytosis’ is a physiological process that maintains tissue homeostasis and promotes cessation of…
Post-translational modulation of a host purine biosynthetic enzyme by Chlamydia trachomatis
1R21AI199320-01REY CARABEO · UNIVERSITY OF NEBRASKA MEDICAL CENTER, NE · $417,845 · awarded Jun 3, 2026 · NIHPROJECT SUMMARY The interaction between host and pathogen is antagonistic, and this is best illustrated by infection of host cells by the obligate intracellular bacterium Chlamydia trachomatis (Ctr). Ctr is absolutely dependent on the host cell for numerous indispensable nutrients, a characteristic that manifest its obligately intracellular nature.…
Exploiting time-of-flight in photon cascade emissions for direct imaging of therapeutic radionuclides
1R21EB037871-01A1Javier Caravaca · UNIVERSITY OF CALIF-LAWRENC BERKELEY LAB, CA · $312,165 · awarded Jun 2, 2026 · NIHProject Summary (Abstract) Radiopharmaceutical therapies (RPT) are extremely promising for cancer treatment. RPT is a rapidly growing treatment modality that has demonstrated a great success in the treatment and care of multiple malignancies. The efficacy of RPTs relies on delivering a very targeted radiation dose to tumor cells, sparing healthy tissue.…
Modeling Myotonic Dystrophy Type 1 and Type 2 (DM1 and DM2) Neuropathology with iPSC-Derived Cortical Organoids
1R21NS149030-01David Butler · REGENERATIVE RESEARCH FOUNDATION, NY · $233,550 · awarded Jun 1, 2026 · NIHRepeat-expansion disorders myotonic dystrophy 1 and 2 (DM1, DM2) produce disabling cognitive and behavioral deficits, yet the molecular drivers of central-nervous-system (CNS) pathology remain undefined. DM1 is caused by expanded CTG repeats in the dystrophia-myotonica protein kinase (DMPK) gene that produces toxic CUG RNAs, whereas DM2 is caused by…
Assessing Access to Language in the Real-World and Neural Language Processing in Preschoolers who are Deaf or Hard of Hearing
5R21DC022038-04Carlos Benitez-Barrera · UNIVERSITY OF SOUTH FLORIDA, FL · $187,500 · awarded May 28, 2026 · NIHChildren acquire language through interactions with their immediate environment, especially at home with their caregivers1. This is particularly relevant in preschool years, a critical period where children’s lifelong language abilities are established2. Insufficient quantity and quality of language exchanges with caregivers in early years increase the risk…
Optimizing Minoxidil Delivery for Persistent Elastin Deposition in the Murine Vaginal Wall
1R21HD118466-01A1MATTHEW BERSI · WASHINGTON UNIVERSITY, MO · $441,884 · awarded May 28, 2026 · NIHPROJECT SUMMARY Pelvic organ prolapse (POP) is an abnormal descent of the female pelvic organs that protrudes to, or through, the vaginal canal. Prolapse is caused by a loss of structural integrity of the pelvic organs and their connective tissue support and coincides with a reduction in vaginal elastic fibers either through enzymatic (as with age) or…
Physiologic effect of abdominal myofascial release (MFR) in irritable bowel syndrome with constipation (IBS-C)
1R21AT013588-01Alain Benitez · CHILDREN'S HOSP OF PHILADELPHIA, PA · $489,500 · awarded May 27, 2026 · NIHSUMMARY Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction with a childhood prevalence of up to 5.1% in the United States, and up to 22.6% worldwide. Children with IBS experience debilitating psychosocial and gastrointestinal (GI) symptoms resulting in impaired quality of life (QoL). IBS with constipation (IBS-C) is a subtype…
Funding institutes in the sample
| Institute | Awards | Funding |
|---|---|---|
| NIH | 495 | $138.0M |
| ALLCDC | 4 | $766K |
| AHRQ | 1 | $140K |
Most frequent institutions in the sample
- JOHNS HOPKINS UNIVERSITY — 19 awards
- MASSACHUSETTS GENERAL HOSPITAL — 13 awards
- WASHINGTON UNIVERSITY — 12 awards
- UNIVERSITY OF PITTSBURGH AT PITTSBURGH — 11 awards
- STANFORD UNIVERSITY — 11 awards
- UNIVERSITY OF CALIFORNIA, SAN FRANCISCO — 10 awards
- UNIVERSITY OF MINNESOTA — 10 awards
- YALE UNIVERSITY — 10 awards
Source: NIH RePORTER. Verify any award in the official record by searching its project number. See our data methodology for how this sample is built and its limitations.
Decision guide
Choose R21 when
Choose R21 when the idea is novel, the preliminary data are minimal or absent, and you can plausibly complete the work in 2 years. Strong R21s typically articulate a clear hypothesis test even without extensive prior work.
Choose another mechanism when
Skip R21 if your project is incremental on existing R01 work — reviewers expect genuine novelty. Skip if you need >2 years or >$275K. Don't use R21 just because you lack data; reviewers are getting stricter about novelty.
Who applies for R21
R21s are commonly used by both new and established investigators. New investigators use R21s to test a novel idea before committing it to an R01 application. Established investigators use them to pivot into adjacent areas or test risky ideas alongside their R01-funded work.
Compare nearby NIH grant mechanisms
Searchers often land on R21 while deciding between adjacent NIH activity codes. Compare scope, NIH staff involvement, budget scale, and applicant stage before choosing a funding opportunity.
Discrete, specified investigator-led research project
Small, short-term projects (pilot studies, secondary analyses, methods development)
Planning for clinical trials or large-scale studies
For broad grant lookup, use the NIH grant search to find funded examples by activity code, PI, institution, and award year.
Search tips for R21
- R21 success rates vary widely — some institutes essentially treat them as small R01s with strict 2-year limits.
- An R21 awarded to a PI sometimes precedes an R01 in the same area within 2–3 years.
Search NIH grants by activity code
Find R21-funded PIs
R21 funding trends
R21 frequently asked questions
What is the page limit for an NIH R21?
The Research Strategy is 6 pages for an R21 (half of an R01).
Do I need preliminary data for an R21?
No. R21 funding announcements explicitly state preliminary data are not required. In practice, strong applications often include some, but the reviewers should not penalize lack of preliminary data per the funding mechanism design.
Can an R21 be renewed?
R21 awards are not renewable. The mechanism is designed for 2 years and out — typically followed by an R01 application if the work proceeds.
What is the typical R21 success rate?
R21 success rates have generally been similar to or slightly lower than R01 rates (typically 12–18%) in recent years. Variation by institute is large.