updated March 2026

Letters of Support document concrete commitments from collaborators, core facilities, and institutions (e.g., effort, access to equipment, samples, or mentoring) rather than serving as general reference letters or letters of recommendation. A Letter of Support for a grant is a means to convey to reviewers that the applying PI has in place the expertise and resources to complete the proposed grant aims. The letter should be succinct and tailored for the specific grant that the PI is applying for. Some funding announcements specify required letters (e.g., institutional commitment for ESIs, multi-component centers, SBIR/STTR institutional/partner letters), so check the NOFO carefully.

Structure of the Letter

Letters of support should be on official letterhead and have formal headers and footers . They should also be dated.

The letter should be addressed to the PI. Each writer can choose their preferred tone, either friendly or formal, and use the salutation to convey that tone. "Dear First Name," and "Dear Professor Last Name," are both acceptable.

The first sentence should convey support and enthusiasm for the proposed research, and include the name of the proposal, and if possible, the application number (and grant number for a renewal). "I am writing to express my support for your application entitled "name of grant", R01######. This is an important project that will impact how the field thinks about [PROBLEM] and how the field goes about testing therapeutics to treat [DISEASE]".

After this, the letter writer should introduce themselves in context to the grant proposal, and state what they will do to support the grant. "I am a professor of [SUBJECT] at [UNIVERSITY]. As an expert in [TYPE OF ANALYSIS] of [TISSUE] samples, I am particularly excited by your plan to monitor [PROCESS] via [ANALYSIS TYPE] of [TISSUE]. I think this approach will be highly productive, as [REASON]. I have the necessary equipment available in my lab, which is in the same building as yours, and am happy to make this equipment available to you as well as to work with you on any [ANALYSIS] issues that arise."

Finally, the writer should sign off with a statement of support, and then include both a signature and full title. "I look forward to working with you on this exciting project. Sincerely, [NAME, TITLE, AFFILIATION]."

The Letter of Support should clearly describe the type and extent of support: what will be provided (reagents, animals, human samples, datasets, specialized analyses, mentorship), under what conditions, and over what timeframe. This can include statements of effort or time commitment (“I will devote approximately 5% effort to…”), any cost-sharing or waived fees (e.g., discounted core rates, institutional support), and expectations regarding authorship, data sharing, and resource availability to others.

Requesting a LOS for a grant

First, whenever emailing a faculty member for an administrative document, always cc their administrative assistant (if they have one) on the email. In your request email, include: proposal title and mechanism, 2–3 bullet points of what you’d like them to state they’ll provide, the due date (and internal deadline), and a draft letter they can edit. Then, let them be. If you have not received the letter two days before the grant is due, send your writer a reminder, again including the draft letter, copying their administrative assistant, and requesting confirmation that they still intend to supply the letter. Be direct, succinct and polite in all communications, but do ensure that your email clearly conveys the urgency. Remember to thank your colleague via an email once the letter is received, and again should your grant be funded. 

Attaching LOS to a NIH grant application

All LOS should be combined into a single pdf and uploaded to your grant application in Section 9 of the Research Plan form on ASSIST.  Order them in the order that the letters are referenced in the grant research strategy. If you are submitting a complex grant with many LOS, you can include a table at the beginning of the combined pdf of letters documenting the number of letters attached, their order, and (for some grants) a brief description of their importance.