Types of Letters for Grant Applications

Know when and how you should provide a letter of intent, cover letter, letters of support, reference letters, and more.

Each key letter plays a different role to inform NIH staff, peer reviewers, or both. Depending on your application type and research plans, some letters may be required while others are optional or should be omitted.

Learn what’s required and how to use each type of letter on the following subpages.

Letters of Intent

Your chosen funding opportunity may request a letter of intent before you apply. We advise you to send one and consult with NIAID staff.

Cover Letters

Check required and optional reasons to include a cover letter with your application.

Letters of Support

Your application must include letters of support from your institution, key personnel, collaborators, and other significant contributors. 

Reference Letters

Some types of programs, such as fellowships (F) or mentored research career development (K) awards, require you to request letters of reference before you apply.

Additional Letters

Beyond the letters listed above, you may need to include other letters with your application or just-in-time.

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