Guide to NIH Fellowship Reference Letters

Posted by Aubrie Stricker on Friday, October 24, 2025 in Announcements, Path to Career Resources .

Reference Letters are a required component of NIH fellowship applications (and they are different than Letters of Support!)

Key points about Reference Letters:

• You must have at least 3 reference letters, but up to 5 can be submitted. You may want to request more than the minimum number in case one of your recommenders does not submit their letters on time.
• Your Sponsor (your PI) and co-sponsors cannot provide Reference Letters. Likewise, individuals directly involved in your application (e.g., collaborators or other Letters of Support writers) are not eligible referees.
• Reference Letters are confidential and thus submitted directly by the referee through the NIH eRA Commons Reference Letter system. Instructions on how to upload the letters can be found here. Applicants cannot upload these letters on behalf of their referees.
• The deadline for referees to submit a Reference Letter is the NIH fellowship application deadline (April 8, August 8, December 8). Late letters are not accepted and applications without at least 3 submitted Reference Letters will not be reviewed.
• Include a list of the referees (including name, departmental affiliation, and institution) in your cover letter so NIH staff are aware of planned reference letter submissions.
• Reference Letter writers are specifically asked to address your:
  • Qualities that will contribute to your success
  • Areas to develop to improve your success
  • Your preparedness & likelihood for success

Tips for choosing referees:

• Review the instructions for letter writers and think about who can best comment on your personal characteristics and areas for development. PhD students should ask previous research mentors, such as scientists who supervised their research during a summer research internship or undergraduate thesis project.
• PhD students should also consider asking their dissertation committee chair or other members of their thesis committee who have seen them present their research or “think on their feet.”
• Postdocs should include their PhD advisor and past collaborators.
• Letter writers should be professional scientists who are at an assistant professor level or above (or an industry equivalent). Refrain from asking postdocs, graduate students, or research staff who have supervised you, unless those individuals are in a professional role (faculty job, etc.) at the time you are applying.
• When you reach out to someone to write a Reference Letter for you, make it easy to write a supportive and personalized letter – provide them with your updated CV, abstract, aims, prompts/reminders.

When you ask someone to serve as a reference, provide them with the following:

• The NIH Reference Letter instructions
• Your name as it appears in your eRA Commons account
• Your eRA Commons Username
• The Funding Opportunity number
• The NIH deadline for submission.
• Your updated CV or NIH biosketch (so they have your accomplishments at their fingertips) and your proposal abstract (so they can comment on your potential to be successful in the proposed project).

More information about Reference Letters can be found here.

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Tags: Fellowships, Grant Writing