NIH F31 Fellowship Application: A Graduate Student's Complete Guide

The NIH F31 is one of the most important funding mechanisms available to predoctoral students in the biomedical and behavioral sciences. It provides a stipend, tuition allowance, and institutional allowance -- but more importantly, it signals to your field that your research training has been peer-reviewed and endorsed by the National Institutes of Health. That stamp matters when you are applying for postdocs, faculty positions, and your first independent grant.

Yet the F31 is not simply a research grant. It is a training grant, and that distinction shapes every section of the application. Reviewers are not just evaluating your science. They are evaluating whether the proposed training plan will transform you into an independent researcher, whether your sponsor can deliver on that plan, and whether the institutional environment can support it.

This guide covers everything you need to know about the F31 application, from eligibility through submission strategy, including the related F30 mechanism for MD/PhD students. I have reviewed and helped write more than forty F31 applications across NIH institutes, and the patterns of success -- and failure -- are remarkably consistent.

F31 vs. F30: Which Mechanism Is Right for You?

The F31 (Ruth L. Kirschstein Predoctoral Individual National Research Service Award) is open to PhD candidates in the biomedical, behavioral, health services, or clinical sciences. You must be enrolled in a research doctoral degree program at a domestic institution and have identified a dissertation research project and sponsor.

The F30 is the dual-degree equivalent, designed for students in combined MD/PhD or DO/PhD programs. The structure is nearly identical to the F31, but the F30 includes additional flexibility for the clinical training phases of a dual-degree program. If you are in an MD/PhD program, the F30 is almost always the correct mechanism.

Both the F31 and F30 follow the same application format and scoring criteria. The strategic advice in this guide applies to both.

Eligibility Requirements

Before you invest weeks in an application, verify that you meet every eligibility criterion. NIH will reject noncompliant applications without review.

Citizenship: You must be a U.S. citizen, a non-citizen U.S. national, or a permanent resident at the time of application. International students on F-1 or J-1 visas are not eligible, regardless of their research qualifications.

Enrollment: You must be enrolled in a PhD program (or combined clinical/research degree program for the F30) at a domestic institution accredited to award the doctoral degree. You do not need to have passed qualifying exams at the time of application, but you should have identified your dissertation topic and sponsor.

Sponsor: You must have an identified sponsor (dissertation advisor) who holds an active, independently funded research program. Co-sponsors are allowed and can strengthen the application, particularly if your research is interdisciplinary.

Stage of training: There is no formal requirement about how far along you must be, but the sweet spot is typically after your qualifying exam and before you are more than halfway through your dissertation data collection. Applying too early means you lack preliminary data. Applying too late means the training plan feels retroactive.

NIH Institute: F31 applications are submitted to a specific NIH Institute or Center (IC). Each IC may have additional requirements or priorities. Check the parent FOA (Funding Opportunity Announcement) and any IC-specific notices.

The Five Scored Review Criteria

NIH study sections evaluate F31 applications on five criteria, each scored from 1 (exceptional) to 9 (poor). Understanding what reviewers are looking for in each criterion is essential.

1. Fellowship Applicant (You)

This is the single most important criterion. Reviewers assess your academic record, research experience, motivation, and potential for a productive scientific career. They want to see:

• A clear trajectory from your early training to your current research interests
• Evidence of increasing independence (publications, presentations, successful mentored projects)
• Research skills relevant to the proposed project
• A thoughtful statement about your career goals and how this fellowship accelerates them

Common mistake: listing accomplishments without connecting them into a narrative. Reviewers want to understand why you chose this research direction, not just that you have lab experience.

2. Sponsors, Collaborators, and Consultants

Reviewers evaluate whether your sponsor has the expertise, funding, and track record to deliver the training described in the application. Key factors include:

• The sponsor's active research funding (an R01 or equivalent is strongly expected)
• Publication record in the area of the proposed research
• History of successfully mentoring predoctoral students to completion
• The sponsor's plan for your training (not your plan -- their plan)

If you have a co-sponsor, the application should make clear why two mentors are necessary and how their expertise complements each other. A co-sponsor who simply signs a letter but has no defined role will raise questions.

3. Research Training Plan

This is equivalent to the research strategy in an R01, but scoped to a dissertation project. It includes your Specific Aims, Significance, Innovation, and Approach. Reviewers evaluate:

• Scientific rigor and feasibility of the research plan
• Whether the project is appropriate in scope for a predoctoral trainee
• Quality and interpretation of preliminary data
• Clear milestones and a realistic timeline

The research plan has a 6-page limit (as of the current FOA). Every sentence needs to earn its space.

4. Training Potential

This criterion evaluates the overall training plan -- coursework, workshops, professional development activities, and mentoring structure. Reviewers want to see:

• A training plan tailored to fill specific gaps in your current skillset
• An Individual Development Plan (IDP) that is specific, not generic
• Concrete plans for acquiring skills you do not currently have
• Opportunities for scientific communication (presentations, manuscript writing)

The key phrase here is "gaps." Identify what you still need to learn to become independent, and show how this fellowship period will close those gaps.

5. Institutional Environment and Commitment to Training

Reviewers assess whether the institution provides the resources, infrastructure, and intellectual environment to support your training. This includes:

• Core facilities relevant to your research
• Other trainees and postdocs in the lab and department
• Seminar series, journal clubs, and collaborative opportunities
• Institutional commitment to diversity and inclusion in training

This criterion is usually the least discriminating -- most research universities score well here. But weak descriptions of institutional resources can drag your score down.

Writing the Specific Aims Page

The Specific Aims page is the most important single page of your application. Reviewers read it first, and many form their initial impression of the application before reading anything else.

For an F31, the Specific Aims should be structured slightly differently than for an R01. You are not proposing a five-year research program. You are proposing a focused dissertation project with 2-3 aims that can be completed within the fellowship period (typically 2-3 years of remaining training).

Opening paragraph: State the problem, its significance, and what is not known. This should be 3-5 sentences that orient the reviewer to the scientific question.

Gap statement: Identify the specific gap in knowledge that your research addresses. Be precise. "Little is known about X" is weak. "The mechanism by which X regulates Y in the context of Z remains undefined, limiting our ability to develop targeted interventions" is stronger.

Long-term goal and objective: Your long-term goal is your career direction. Your objective is what this particular project will accomplish. These are distinct.

Central hypothesis: State your hypothesis clearly. It should be testable and directly tied to your aims.

Specific Aims (2-3): Each aim should be a complete, testable objective. Aims should be related but not dependent -- if Aim 1 fails, Aim 2 should still be viable. For each aim, include 1-2 sentences describing the approach and expected outcome.

Impact statement: Close with why this work matters for the field and for public health. For an F31, you can also briefly note how the project contributes to your training goals.

The Applicant's Background and Goals Statement

This section (limited to 6 pages) is unique to fellowship applications and does not appear in R-series grants. It has two components: your background and your goals.

Background

Describe your research experience chronologically, but make it a narrative, not a CV in prose form. For each significant experience, explain:

• What the project was about
• What your specific contribution was
• What skills you gained
• How it led to your current research direction

Publications and presentations should be woven into the narrative, not listed separately (those go in the biosketch). The goal is to show intellectual growth and increasing independence over time.

Goals

Your goals should address three time horizons:

During the fellowship: What specific skills, knowledge, and competencies will you develop? Be concrete. "I will learn advanced microscopy techniques" is vague. "I will develop proficiency in two-photon calcium imaging and computational analysis of neural circuit dynamics under the mentorship of Dr. Smith, whose lab has published extensively on these methods" is specific and verifiable.

Short-term career goals (3-5 years post-fellowship): What will you do after your PhD? Postdoc in a specific area? Industry research position? Be realistic and specific.

Long-term career goals: What type of independent research program do you want to build? What problems will you work on? This section should connect logically to the training you are proposing.

Sponsor and Co-Sponsor Statements

The sponsor's statement is written by your advisor, but you should be heavily involved in shaping its content. This is not an arm's-length letter of recommendation. It is a structured document that must address specific elements.

What the Sponsor Statement Must Cover

Research support: List the sponsor's active grants. An unfunded sponsor is a significant red flag for reviewers.

Training plan: The sponsor must describe a concrete plan for your training, including regular meetings, milestones, and how they will promote your independence. Generic statements like "I will meet with the trainee regularly" are insufficient. Specifics matter: "We will meet weekly to review data and experimental plans. At months 6, 12, and 18, we will conduct formal progress reviews against the milestones in the training plan."

Previous trainees: Where are the sponsor's former students and postdocs now? Reviewers want to see a track record of trainees who completed their degrees and went on to productive careers.

Number of current trainees: If your sponsor has ten graduate students, reviewers may question whether you will receive adequate individual attention. If this is the case, explain how your mentor structures their time across trainees.

Selecting a Co-Sponsor

A co-sponsor is not required, but adding one can strengthen your application if:

• Your research spans two disciplines (e.g., computational and experimental)
• You need training in a methodology your primary sponsor does not use
• You are working at the interface of two labs with complementary expertise

Do not add a co-sponsor simply to pad the application. If the co-sponsor's role is not clearly distinct from the sponsor's, reviewers will view it as a weakness.

Letters of Reference

F31 applications require 3-5 letters of reference. Your sponsor typically writes one. The remaining letters should come from individuals who can speak to different aspects of your qualifications:

• A previous research mentor (from your undergraduate institution or a rotation)
• A collaborator who has worked with you directly
• A faculty member who has observed your academic or professional development

Strategy: Contact referees at least 6 weeks before the submission deadline. Provide each with your specific aims page, your background and goals statement, and a brief note about what you would like them to emphasize. Do not assume your referees know what NIH reviewers are looking for -- give them the information they need to write an effective letter.

Letters that are generic ("Student X is hardworking and intelligent") will not help. Letters that are specific ("Student X independently troubleshot the CRISPR knock-in protocol, identified a critical issue with the guide RNA design, and ultimately generated the mouse line that enabled our recent publication in Cell Reports") are the ones that move scores.

Training Environment and Institutional Support

This section documents the resources available to you at your institution. While it is scored, it is usually not the deciding factor in a competitive review. However, a weak institutional environment section can create doubt about whether the training plan is feasible.

Include:

• Core facilities you will use, with specific names and capabilities
• Coursework relevant to your training plan (list specific courses)
• Training programs such as T32 grants in your department, responsible conduct of research training, and career development workshops
• Collaborative environment including seminars, journal clubs, and interdepartmental programs
• Diversity and inclusion initiatives in your department or institution

Paylines and Funding Expectations

Paylines vary significantly across NIH Institutes and Centers. Some ICs fund F31 applications with impact scores in the low teens (e.g., NIGMS, NIMH), while others have tighter paylines. The diversity supplement F31s (F31 Diversity) often have more favorable paylines than the standard F31.

As a rough guide, a percentile score of 20 or below puts you in a competitive range at most ICs. Scores in the single digits are funded at virtually all ICs. But these numbers change with congressional appropriations and IC priorities, so check the most current payline information on your target IC's website.

The F31 Diversity mechanism (PA-25-series) is specifically for students from underrepresented backgrounds. If you are eligible, this mechanism has historically had more favorable funding rates and is worth serious consideration.

Timeline and Submission Strategy

NIH has three standard receipt dates for fellowship applications: April 8, August 8, and December 8 (or the next business day if these fall on a weekend). The review cycle takes approximately 5-6 months from submission to funding decision.

A realistic preparation timeline:

• 6 months before deadline: Identify your mechanism, confirm eligibility, discuss the application with your sponsor
• 4 months before: Draft specific aims, begin the research training plan
• 3 months before: Complete first draft of the full application, request letters of reference
• 2 months before: Internal review by your sponsor and colleagues, revise based on feedback
• 1 month before: Final revisions, institutional review and sign-off
• 2 weeks before: Upload to eRA Commons, resolve any formatting issues

Do not underestimate the time required for institutional sign-off. Many universities require 5-10 business days for grants office review.

Common Reasons F31 Applications Score Poorly

Based on reviewer feedback across dozens of F31 applications, these are the most frequent criticisms:

Lack of preliminary data. You do not need extensive data, but you need enough to demonstrate feasibility. At minimum, show that you can execute the methods you are proposing.

Generic training plan. "I will attend seminars and take courses" is not a training plan. Specify which seminars, which courses, what skills gaps they address, and how you will measure your progress.

Overly ambitious scope. Your dissertation project should be completable within 2-3 years. If reviewers think your aims would take a full postdoc to complete, your feasibility score will suffer.

Disconnected sponsor statement. If your sponsor's statement does not reference the specific training activities described in your application, reviewers will question whether the sponsor is actually invested in your development.

Weak career goals. Vague statements about "pursuing a career in biomedical research" do not demonstrate thoughtful planning. Identify the specific type of position you want, what training you still need, and how this fellowship gets you there.

Resubmission Strategy

If your F31 is not funded on the first submission, you can resubmit once (as an A1 application). The resubmission must include a one-page Introduction addressing the reviewers' critiques.

Key principles for a successful resubmission:

• Address every critique, even ones you disagree with
• If you disagree with a critique, provide additional data or citations -- do not simply argue
• Generate new preliminary data if feasibility was questioned
• Revise the training plan if reviewers found it generic or incomplete
• Update your biosketch and background statement with any new accomplishments

Resubmissions historically have higher success rates than initial submissions, because you know exactly what the reviewers want to see.

Final Advice

The F31 is not just a funding mechanism. It is a career development exercise. Writing the application forces you to articulate your scientific identity, your training needs, and your career trajectory in a way that few other exercises require at the predoctoral stage.

Take the process seriously, start early, and use the application as an opportunity to have honest conversations with your sponsor about your training and career goals. The best F31 applications I have reviewed are the ones where the applicant and sponsor clearly sat down together, identified specific training gaps, and built a plan to close them.

Tools like Granted AI can help you analyze the FOA, structure your application around NIH's specific requirements, and ensure your narrative covers every scored criterion. But the substance -- your science, your goals, your training plan -- has to come from you and your mentor.

Keep Reading

• NIH Grant Writing Tips for Early-Career Researchers
• NSF GRFP Application Guide
• Navigating NIH Funding Mechanisms: Decoding R, K, and F Series Grants
• See how Granted AI structures fellowship applications

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