What is the NIH F31 fellowship?

The NIH F31 is the Ruth L. Kirschstein National Research Service Award (NRSA) Individual Predoctoral Fellowship. It provides funding to promising PhD students for dissertation research in biomedical, behavioral, or clinical sciences. The award covers a stipend (~$28,224/year as of FY2025), tuition/fees (up to $16,000/year), and an institutional allowance ($4,200/year).

Who is eligible for the NIH F31?

Applicants must be U.S. citizens, non-citizen nationals, or permanent residents. They must be enrolled in a research doctoral degree program (PhD or equivalent) in a biomedical, behavioral, or clinical science field at a domestic institution. Most successful applicants are in years 2-4 of their PhD program.

What are the NIH F31 submission deadlines?

Standard F31 submission deadlines are April 8, August 8, and December 8 each year for most parent funding opportunity announcements (FOAs). Some institute-specific FOAs have different deadlines, so always check the specific FOA you're applying to.

How does the F31 compare to the NSF GRFP?

The F31 and NSF GRFP differ in several ways. The F31 pays ~$28,224/year (FY2025) for up to 5 years and is best applied for in years 2-4 of a PhD, while the NSF GRFP pays $37,000/year for 3 years and is typically applied for as a senior undergrad or in the first year of a PhD (before completing one academic year). The F31 requires U.S. citizenship or permanent residency, and the NSF GRFP has its own citizenship and residency rules that should be checked against the current NSF solicitation. The NSF GRFP is portable across institutions; the F31 requires a new application if you transfer.

Scope: F31 eligibility · application components · scoring · deadlines·Data: NIH OER, NIH Reporter, individual IC funding policies·Last reviewed: March 2026·Source: Manusights editorial team (researchers with publications in Cell, Nature, Science)·Cite this guide ↓

NIH F31 Fellowship: Complete Guide for PhD Students

The F31 is the NIH's predoctoral fellowship for PhD students doing dissertation research in biomedical, behavioral, or clinical sciences. It's one of the most common ways graduate students get their own NIH funding. and having one on your CV tells future reviewers and hiring committees that your work passed independent peer review before you even finished your degree.

This guide walks through every part of the F31: who's eligible, what the award covers, how to write each application component, what reviewers score, and the mistakes that sink otherwise strong applications. Sources are cited in the references section below.

What Is the NIH F31?

The full name is the Ruth L. Kirschstein National Research Service Award (NRSA) Individual Predoctoral Fellowship, though most people just say "F31." There are actually two parent funding opportunity announcements (FOAs):

F31 (Standard)

Parent FOA: PA-23-272. Open to all eligible predoctoral students regardless of background. This is the broader fellowship that any qualifying PhD student can apply for.

Typical success rate: 20–30% depending on the institute

F31 Diversity

Parent FOA: PA-23-271. For students from groups underrepresented in biomedical research, including racial/ethnic minorities, students with disabilities, and students from disadvantaged backgrounds. Includes an extra $5,000/year institutional allowance.

Typical success rate: Generally higher paylines than standard F31

Both versions fund up to 5 years of predoctoral research training, though most awards are for 2–3 years. The fellowship is administered through individual NIH institutes and centers (ICs), which means your application goes to whichever IC best matches your research area. NINDS for neuroscience, NCI for cancer, NHLBI for heart/lung/blood, NIAID for immunology, NICHD for developmental biology, and so on. Each IC has its own payline and budget, so funding rates vary.

Eligibility Requirements

Citizenship

You must be a U.S. citizen, non-citizen national, or permanent resident at the time of the award. International students on visas (F-1, J-1, H-1B) are not eligible. This is a hard rule with no exceptions.

Degree program

You must be enrolled in a research doctoral degree program (PhD, MD/PhD, or equivalent) at a domestic institution. The program must be in a biomedical, behavioral, or clinical science. Professional degrees alone (MD, DDS, DVM) don't qualify unless combined with a research doctorate.

Stage of training

There's no formal year requirement, but NIH expects you to have passed qualifying exams or be close to doing so. Most successful applicants are in years 2-4 of their PhD. Applying in year 1 is possible but harder because you'll have less preliminary data. Applying after year 4 is risky because reviewers may question whether you need fellowship support to finish.

Sponsor

You need a primary dissertation advisor (sponsor) who agrees to mentor you through the fellowship. The sponsor must have an active research program and a track record of mentoring predoctoral students. Co-sponsors are allowed and sometimes strengthen the application if they bring complementary expertise.

Institution

Your institution must be a domestic, for-profit or non-profit, public or private institution of higher education (e.g., universities, medical schools). The institution handles the administrative side of the grant.

What the F31 Pays

The F31 isn't going to make you rich, but it covers the basics and, more importantly, frees you from TA duties and gives you protected research time. Here's what the award includes:

Component	Amount	Notes
Stipend	$28,224/year (FY2025)	Set by NIH, adjusted annually. Not considered salary. it's a "living allowance." You don't pay FICA taxes on it, though it's still taxable income. Verify current rates at grants.nih.gov before applying. These figures are updated annually.
Tuition & fees	Up to $16,000/year	Covers 60% of tuition up to the cap. Your institution pays the rest. Some programs waive tuition for funded students anyway.
Institutional allowance	$4,200/year	Covers health insurance, research supplies, travel to conferences. Your institution decides how it's allocated.
F31 Diversity bonus	+$5,000/year institutional allowance	Only for F31 Diversity (PA-23-271) awardees. Brings the institutional allowance to $9,200/year.

Note on stipend levels: NIH updates NRSA stipend levels annually. Check the current NIH NRSA stipend table at grants.nih.gov before budgeting your application. Rates increase most years.

Application Components: What You Need to Write

The F31 application has more pieces than a typical R01, and each one matters. Here's what goes into the package and what reviewers are looking for in each section.

Specific Aims (1 page)

This is the single most important page of your application. Reviewers form their first impression here, and many will have made up their mind about your score before they finish reading it. You get exactly one page.

Structure that works: Open with a paragraph establishing the problem and why it matters (3–4 sentences). Then state the gap in knowledge. what don't we know yet? Follow with your long-term goal, the objective of this fellowship, and your central hypothesis. Then list 2–3 specific aims with one sentence of approach for each. Close with a "payoff" paragraph: what will we know when this work is done?

Common mistakes on the Aims page: Packing in too much background instead of getting to the point. Listing 4+ aims (stick to 2–3). Making aims interdependent so that if Aim 1 fails, the rest collapse. Using jargon that a reviewer outside your exact subfield won't follow. Not stating a testable hypothesis.

Research Strategy (6 pages)

This follows the standard NIH format: Significance, Innovation, and Approach. For the F31, you get 6 pages total (not 12 like an R01). That's tight. Every sentence needs to earn its place.

Significance (~1 page)

Why does this research matter? What problem are you addressing, and what's the current state of the field? Don't write a literature review. write a focused argument for why this specific gap needs filling. Tie it to human health outcomes when possible (NIH cares about this). End with a clear statement of what your project will change.

Innovation (~0.5–1 page)

What's new about your approach? This doesn't mean you need to invent a new technique. Using an established method in a new context, combining approaches that haven't been paired before, or studying a question no one's asked. all of these count. Be specific about what you're doing differently and why it matters. Avoid vague claims like "this is the first study to..." unless it genuinely is.

Approach (~4–4.5 pages)

This is the bulk of your Research Strategy. For each aim, describe: the rationale (why this aim), the experimental design, methods, expected outcomes, potential pitfalls, and alternative approaches. Include preliminary data. reviewers want evidence that you're capable of doing this work and that the project is feasible. A figure showing pilot data can be worth half a page of text. Don't propose more experiments than you can finish in the award period.

What matters most for F31 Research Strategy: Feasibility. Reviewers know you're a trainee. They don't expect R01-level depth, but they do expect a realistic plan that you can actually execute. Show preliminary data, include power calculations where relevant, and have clear contingency plans. Proposing too much is the #1 Approach critique on F31s.

Training Plan & Career Goals

This is where the F31 differs most from an R-series grant. The F31 is a training award, not just a research award. Reviewers want to see that this fellowship will teach you specific new skills you don't already have and that you have a clear plan for your career.

What reviewers actually want to see:

Specific new skills you'll gain during the fellowship (not skills you already have). Name the techniques, courses, or methods. "I'll learn CRISPR screening from Dr. Smith's lab" is better than "I'll develop expertise in genetic tools."
A mentorship plan with named individuals. Who's your primary sponsor? Do you have a thesis committee? Any co-mentors for specific techniques? How often do you meet?
Career milestones with a timeline. When will you present at a conference? Submit your first paper? Defend your thesis? Start postdoc applications?
Career goals beyond the PhD. Whether you're aiming for academia, industry, policy, or something else, spell it out. Reviewers want to fund someone who's thought about where they're going.

Common mistake: Writing the training plan as an afterthought. On R01 applications, the research drives the score. On the F31, the training and career development components are weighted equally with the research. A strong Research Strategy with a vague Training Plan will score poorly.

Sponsor Statement & Letters of Support

Your sponsor (PI/advisor) writes a letter describing their commitment to your training, their mentoring approach, their lab's resources, and their own qualifications as a mentor. This letter matters more than most applicants realize. A generic, template-sounding sponsor letter is a red flag.

The sponsor statement should address: their mentoring track record (previous trainees and where they are now), how they'll ensure you develop independence, the training environment in the lab, and how this project fits within the lab's ongoing work without being a subsection of the PI's R01.

You'll also need 3–5 reference letters from faculty who know your work. These should come from committee members, collaborators, or rotation advisors. people who can speak specifically about your research abilities.

Biosketch

Use the standard NIH biosketch format. As a predoctoral student, you probably don't have many publications yet. that's fine. Include preprints, presentations, and published abstracts. The personal statement at the top of the biosketch should connect your background directly to this fellowship: why you're prepared for this specific project and training plan.

How F31 Applications Are Scored

F31 applications are reviewed by an NIH study section, typically a fellowship-specific panel. Each application gets 3 assigned reviewers who score it on five criteria:

Fellowship Applicant

Scored 1-9

Your academic record, research experience, potential, and commitment to a biomedical research career. Publications help, but reviewers understand that many PhD students don't have first-author papers yet.

Sponsors, Collaborators, and Consultants

Scored 1-9

Quality of your mentoring team. Does the sponsor have a track record of training predoctoral students? Is the mentoring plan specific? Are there additional mentors who add genuine expertise?

Research Training Plan

Scored 1-9

Scientific merit of the proposed research AND the quality of the training activities. This is where Significance, Innovation, and Approach live, but they're evaluated alongside the training components.

Training Potential

Scored 1-9

Will this fellowship actually add to your skills? Is the training environment appropriate? Does the institutional environment have courses, seminars, and resources that support your development?

Institutional Environment

Scored 1-9

Facilities, equipment, research community. Major research universities score well here by default, but you still need to describe specific resources relevant to your project.

From scores to funding: Each reviewer gives individual criterion scores (1–9, where 1 is best) and an overall impact score. The three reviewers' impact scores are averaged, then multiplied by 10 to give a final impact score from 10 (best) to 90 (worst).

This score is converted to a percentile ranking based on all applications reviewed in that round. Whether you get funded depends on the payline of the specific IC your application went to. Paylines vary: some ICs fund applications with percentiles up to the 25th, while others are tighter at the 15th. Check your target IC's website for their current payline.

Submission Deadlines and Timeline

Deadline	Review	Earliest Start
April 8	June/July	The following April
August 8	October/November	The following August
December 8	February/March	The following December

The gap between submission and funding is roughly 10–12 months. That means if you submit in April 2026, you won't start receiving funds until April 2027 at the earliest. Plan accordingly. you need bridge funding for that gap.

Institute-specific deadlines: Some NIH ICs have their own FOAs with different deadlines. Always check the specific FOA you're applying to. The dates above apply to the standard parent announcements (PA-23-271 and PA-23-272).

Common Mistakes That Sink F31 Applications

Having read hundreds of F31 summary statements, these are the problems that come up again and again:

✗Too much background, not enough specifics. Your Research Strategy isn't a review paper. Get to your experiments faster.

✗No clear career development narrative. The F31 is a training grant. If reviewers can't see how this fellowship advances your career, the score suffers.

✗Weak Sponsor section. A one-page letter that reads like a template tells reviewers your advisor isn't invested. The sponsor letter should be detailed and specific to you.

✗Proposing too many experiments. Three years of work crammed into a 6-page strategy screams infeasible. Scale back and show depth over breadth.

✗Aims that depend on each other. If Aim 2 requires Aim 1 to work perfectly, and Aim 1 is risky, your whole proposal looks fragile.

✗Ignoring the training plan. Spending 90% of your effort on the Research Strategy and dashing off the training components. Reviewers score both.

✗No preliminary data. You don't need a full paper's worth, but pilot experiments showing feasibility make a massive difference.

✗Not tailoring to the IC. Each NIH institute has priorities. A proposal about cancer biology sent to NINDS will confuse reviewers. Know your target IC.

Resubmission (A1): Responding to Reviewers

If your F31 isn't funded on the first try, you get one resubmission (called an A1). Many successful F31 awardees were funded on their A1, so don't treat a first rejection as a dead end.

Your A1 includes a 1-page Introduction that explains how you've addressed the reviewers' concerns. This page is the first thing reviewers read, and it sets the tone for the entire resubmission. Be direct and specific: "Reviewer 2 noted that Aim 1 lacked statistical power. We've now included a power analysis (Approach, p. 3) and increased our sample size from 20 to 45."

✓Address every concern, even minor ones. Acknowledge the reviewer's point, then explain what you changed.

✓Add new preliminary data if you have it. Nothing silences feasibility concerns like results.

✓Restructure sections that were confusing. If multiple reviewers misunderstood the same thing, the writing was the problem.

✗Don't argue with reviewers unless they're factually wrong. Even then, be diplomatic.

✗Don't submit a minimally revised application hoping for nicer reviewers. Study sections can tell.

If your A1 isn't funded, you can submit a new application (A0) with a substantially revised project. but at that point, consider whether the timeline still makes sense for your PhD.

F31 vs. NSF GRFP: Side-by-Side Comparison

These are the two main predoctoral fellowships in the U.S. for biomedical/STEM students. They're not mutually exclusive. you can hold both sequentially (though not simultaneously). Here's how they compare:

Feature	NIH F31	NSF GRFP
Stipend	$28,224/year (FY2025)	$37,000/year
Tuition	Up to $16,000/year	$16,000 cost-of-education allowance
Duration	Up to 5 years	3 years of support over 5-year period
Best time to apply	Years 2-4 of PhD	Senior undergrad or first year of PhD (before completing 1 academic year)
Citizenship	U.S. citizen or permanent resident	U.S. citizen, national, or permanent resident
Portability	Tied to institution (new application to transfer)	Fully portable across institutions
Review focus	Research plan + training + mentorship	Intellectual merit + broader impacts (research plan less detailed)
Scope	Biomedical, behavioral, clinical sciences	All STEM fields + social sciences
Application length	~25-30 pages total	~8 pages total (shorter)
Can hold both?	Yes, sequentially	Yes, sequentially

Strategy note: Many students apply for the NSF GRFP early (before or during year 1) and the F31 later (years 2–3) once they have preliminary data. If you win the GRFP, you can use the F31 after the GRFP period ends. Having both on your CV is a strong signal when applying for postdocs or faculty positions.

References

NIH Office of Extramural Research. Ruth L. Kirschstein National Research Service Award (NRSA) Individual Predoctoral Fellowship (Parent F31). PA-23-272. [grants.nih.gov ↗]
NIH Office of Extramural Research. Ruth L. Kirschstein NRSA Individual Predoctoral Fellowship to Promote Diversity in Health-Related Research. PA-23-271. [grants.nih.gov ↗]
NIH Center for Scientific Review. Fellowship (F) Application Review. Retrieved March 2026. [public.csr.nih.gov ↗]
NIH Office of Extramural Research. NRSA Stipend Levels. Retrieved March 2026. [grants.nih.gov ↗]
NIH Office of Extramural Research. SF424 (R&R) Application Guide for NIH and Other PHS Agencies. Retrieved March 2026. [grants.nih.gov ↗]
National Science Foundation. Graduate Research Fellowship Program (GRFP). Program Solicitation NSF 24-591. 2024. [nsf.gov ↗]

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