Reference Letters vs. Letters of Support

Reference letters and letters of support provide key information for reviewers and NIH staff. Check out the table below for an overview of when each letter is used, who writes them, and what should be included.


Reference Letters

Letters of Support

When are they used?

Used in Fellowships, mentored Career Development Awards, and other programs as requested

Used to demonstrate:  
-Institutional commitment or resources
-Collaboration or role in the project
-Potential or current user of a resource or service proposed in the application

Who writes them?

Referees should be individuals not directly involved in the application, but who are familiar with the applicant’s qualifications. The sponsor/co-sponsor(s) cannot be counted toward the 3 required references.

Collaborators, key personnel, institution, and other significant contributors to the scientific development or execution of the project

What should be included?

-Describe qualities and potential of candidate
-Letters can be addressed to “To Whom It May Concern” or “Dear Reviewer”

-Describe the type of support your collaborators will provide to the project
-Summarize the agreements you have in place to support your project

Who submits them?

A referee submits the letters through eRA Commons (no login needed). The letters are maintained separate from the corresponding application.

Applicant organization submits the letters of support as part of the application.

Who sees them?

Only reviewers and select NIH staff

Anyone with access to view the application

Where are the instructions?

-Reference Letters page
-Special instructions may also be found in funding opportunity announcements and notices

-“Application form instructions” on the How to Apply – Application Guide page.
-Special instructions may also be found in funding opportunity announcements and notices (including Notices of Special Interest)


For more information, see the Reference Letters FAQ page. The National Institute of Allergy and Infection Diseases (NIAID) also has helpful advice on Letters of Support.

Additional References:

Additional information can be found at on OGCA’s website: