Does your application need a cover letter? In some cases, it does, in others, it is optional.  Note that only the scientific review officer sees your cover letter, not the reviewers or program officers.

When a Cover Letter Is Required

You must have a cover letter for the following:

• Approvals to submit. For applications requiring our approval to submit, state that you have attached a copy of the NIAID acceptance letter to the PHS 398 Cover Letter attachment for:
  • Grants requesting $500,000 or more in direct costs for any year.
  • Conference grants (R13 or U13).
  • Investigator-initiated clinical trial planning and implementation awards.
• Genomic data. Explain that the proposed study will generate large-scale human or non-human genomic data. Also note if you plan to access data in the NIH genome-wide association study (GWAS) data repository.
• Corrected applications. Include a complete cover letter if you did not pass validations and submitted a corrected application.
• Late applications. Include the reason your application is late. Learn more at Late Applications and Post-Submission Materials.
• Continuous submission. Indicate that you are a member of an NIH study section qualified to submit at a nonstandard time.
• Video. Indicate that you plan to send video files later.  

Optional Uses for the Cover Letter

You may choose to use a cover letter for the following purposes:

• Point out RFAs and PAs. State the title if you're responding to an initiative.
• Note special areas. Note the involvement of human subjects, select agents, or other areas with special requirements.
• Note a subaward that will be active for only some of the grant's years.

In the past, applicants also used the cover letter to list expertise needed to review the application and to request assignment. Use the PHS Assignment Request Form instead.

Creating Your Cover Letter

Here's how to create and format your cover letter:

• Start with the title and a brief description of your application.
• Use the PHS 398 Cover Letter File in the grant application package—don't confuse it with the mandatory PHS 398 Cover Page Supplement form.

Follow the format NIH gives you in the SF 424 Form Instructions.