- ✓ $800B+ in federal grants distributed annually across 26+ agencies (Grants.gov, FY2025)
- ✓ All federal grants require SAM.gov registration with a UEI number — allow 2–4 weeks before applying
- ✓ NIH success rates average 20–22%; NSF averages 25–28% — preparation and resubmission are critical
- ✓ From application to award typically takes 3–12 months; NIH review cycles run ~9 months
- ✓ Post-award reporting requirements are governed by 2 CFR Part 200 (OMB Uniform Guidance) for all federal awards
Letter of Intent for Federal Grants: When It's Required and How to Write One
The Letter of Intent is one of the most misunderstood steps in the federal grant application process. Many applicants skip it when it is optional, overthink it when it is required, or confuse it with the foundation Letter of Inquiry. This guide clarifies exactly what the LOI is for, when it matters, what to include, and how to write one efficiently.
A federal grant LOI is a non-binding administrative notice that you intend to submit a full application. NIH LOIs are typically due 30 days before the application deadline. They are 1–2 pages and include: project title, PI name and institution, a 250-word abstract, key collaborators, and estimated budget. The LOI does not affect merit review — reviewers never see it. Always check the specific NOFO for whether an LOI is required or optional.
What Is a Letter of Intent?
In the context of federal grant applications, a Letter of Intent (LOI) is a brief, non-binding document submitted to the awarding agency before the full application deadline to notify program staff that your organization intends to submit a complete application for a specific funding opportunity. It is an administrative tool — not a scientific or programmatic review document — and its primary purpose is to help the agency plan for the review process.
Federal agencies use LOI submissions to estimate how many applications they will receive for a given competition, which allows them to plan reviewer recruitment and workload allocation before applications arrive. If a program office expects 50 applications based on LOIs but receives 200, they have a recruiting problem with their review panels. Conversely, if LOI submissions are sparse, the agency may use that signal to extend deadlines, increase outreach, or adjust reviewer capacity. The LOI serves the agency's planning function far more than the applicant's competitive function.
The LOI is typically submitted several weeks before the full application deadline — most commonly 30 days prior in NIH programs, though this varies by agency and program. Because it is non-binding, submitting an LOI does not obligate you to submit a full application, and declining to submit a full application after submitting an LOI carries no penalty. Similarly, in most programs (there are exceptions, discussed below), not submitting an LOI does not disqualify you from submitting a full application.
Understanding the LOI's administrative rather than competitive function helps demystify it. Many first-time federal applicants invest significant time crafting a lengthy, polished LOI because they assume it is an early screening step — that the agency reads LOIs and filters applicants before the full review. In almost all federal competitive grant programs, this is not the case. Program staff may glance at LOIs to verify basic eligibility and plan reviewer assignments, but LOIs do not undergo merit review and do not influence scoring of the full application.
When LOIs Are Required vs Recommended
The single most important thing to know about LOIs is that their status — required, strongly encouraged, optional, or not requested — varies by program. There is no universal federal grant rule; each Notice of Funding Opportunity specifies its own LOI requirements. Reading the NOFO carefully is the only reliable way to determine whether an LOI applies to your situation.
Required LOI: Some NOFOs explicitly state that an LOI must be submitted as a condition of submitting a full application. In these cases, failure to submit the LOI by the specified deadline may result in the application being returned without review. This is relatively uncommon among general federal competitive grants but occurs in certain specialized programs, particularly those managed by smaller program offices that need firm head counts for review planning. The NOFO will typically say something like "A letter of intent is required for this funding opportunity" and provide a firm due date.
Strongly encouraged / requested: The most common language in NIH and many other agency programs. The NOFO will request an LOI and provide a due date, but explicitly states that the LOI is non-binding and that failure to submit one will not prevent application submission. "Strongly encouraged" is the standard NIH formulation. In practice, submitting a requested-but-optional LOI is advisable — it signals professional practice and costs very little time given the short format required.
Optional: Some NOFOs mention that applicants "may" submit an LOI if they choose. This is a genuine option — the LOI provides the agency with useful planning information, but there is no expectation that it will be submitted. In this case, submitting an LOI is a courtesy but not a competitive consideration either way.
Not mentioned: If the NOFO does not mention an LOI at all, none is expected or required. Do not submit an unsolicited LOI to a program that has not requested one — it creates unnecessary administrative burden for program staff and signals unfamiliarity with the specific program's processes.
- NIH LOI due date: typically 30 days before the application deadline for most mechanisms
- LOI is non-binding in the vast majority of federal programs — submitting does not obligate you to apply
- Standard LOI length: 1–2 pages, or character-limited online form fields
- Key elements: project title, PI name and institution, abstract (~250 words), collaborators, budget estimate
- LOIs are used by agencies for reviewer recruitment planning — not early merit screening
- Late LOI: rarely disqualifies but may delay reviewer assignment in some programs
- Foundation "LOI" (Letter of Inquiry): different document entirely — a pre-application screening step requiring agency approval
NIH Letter of Intent Requirements
NIH is the federal agency most associated with the LOI process because many of its high-volume funding opportunity announcements (FOAs) explicitly request one, and NIH's guidance on LOI content is among the most standardized in the federal grant world. Understanding NIH's LOI expectations provides a model that transfers to many other federal agency programs.
For most NIH FOAs, the LOI is due approximately 30 calendar days before the application due date. Some programs with multiple deadlines per year request an LOI for each cycle. The FOA's Section IV (Application and Submission Information) is where LOI requirements and due dates are specified — always check this section rather than relying on the program description, which may not mention the LOI at all.
NIH LOIs are typically submitted by email to the Scientific/Research Contact listed in the FOA, or through the NIH eRA Commons system for programs that have integrated LOI submission into their electronic workflow. The submission method will be specified in the FOA. Do not submit the LOI through Grants.gov — NIH LOIs go directly to the program office, not through the application submission portal.
NIH's published guidance on LOI content is clear and consistent across most of its programs. A standard NIH LOI should include:
- The descriptive title of the proposed application
- Name, address, and telephone number of the Principal Investigator
- Names of other key personnel
- Participating institutions (the applicant institution and any major collaborating institutions)
- Number and title of the FOA to which the application will respond
- A brief description of the proposed work (typically not to exceed 250 words)
NIH is explicit that the LOI is non-binding: "Receipt of a letter of intent will not influence the review or funding decision." This language appears in most NIH FOAs that request an LOI, and it means exactly what it says. The scientific review group (study section) that will evaluate your application does not receive your LOI. The LOI goes to program staff in the institute or center; the application goes through a separate review process managed by the Center for Scientific Review (CSR) or the relevant institute's review office.
One practical implication of NIH's 30-day LOI timeline: when you submit your LOI, your project title and abstract commitment are visible to program staff but are not binding. If your project evolves significantly between the LOI and application submission — as often happens during the full development process — that is acceptable. Do not feel constrained to the exact LOI abstract when writing the full application. The LOI is a planning document, not a contract.
NSF and Other Agency LOI Rules
NSF's approach to LOIs differs from NIH's and varies by program. Many NSF programs do not request LOIs at all — the majority of NSF solicitations go directly to full proposal submission without a preliminary step. However, some NSF programs, particularly those with limited competition or high program officer involvement (like certain Mid-Scale Research Infrastructure awards, some center-scale programs, and Convergence Accelerator tracks), do require or request preliminary proposals, letters of intent, or concept outlines before inviting full proposals.
When NSF requests a preliminary proposal or LOI, the stakes are sometimes higher than in a typical NIH LOI process. Certain NSF programs use preliminary proposals as a genuine screening step — only applicants who receive positive responses are invited to submit full proposals. In these cases, the preliminary proposal functions more like a foundation Letter of Inquiry than a traditional federal LOI. Read the NSF solicitation carefully to determine whether preliminary submissions are a full screening step or an administrative planning tool.
For programs outside NIH and NSF, LOI requirements vary widely. The Department of Energy (DOE) and its Advanced Research Projects Agency (ARPA-E) frequently use concept papers and letters of intent as mandatory first-stage screening for programs with anticipated high application volume. ARPA-E's process in particular is rigorous — concept papers are reviewed against program goals and applicants receive explicit invitation (or discouragement) before full application submission. USDA NIFA programs sometimes request optional LOIs. HUD competitive grants, DOJ programs, and HRSA programs generally do not use LOIs, with program-specific exceptions.
The practical guidance for any program: read Section IV of the NOFO before beginning application development, and check specifically for LOI language. If uncertain, contact the program officer listed in Section G of the NOFO and ask directly whether an LOI is expected and when it is due. This is a completely routine question that program officers answer regularly.
What to Include in an LOI
The content of a federal grant LOI is intentionally limited. Remember that the LOI's purpose is administrative — to give the agency enough information to plan its review process, not to make a scientific or programmatic case for your project. This should govern every content decision you make when drafting one.
Project Title. Use the working title of your proposed project. It does not need to be the final title, though consistency between your LOI title and application title helps program staff match the LOI to the application. The title should be descriptive enough to convey the general topic area — this helps with reviewer assignment planning.
Principal Investigator Information. Include the PI's full name, degree(s), title, institution name, department, mailing address, phone number, and email address. For multi-PI applications, include contact information for the overall PI (designated Contact PI at NIH) and note that co-investigators will be involved.
Key Personnel and Participating Institutions. List the names and institutions of senior/key personnel who will contribute substantially to the project. You do not need complete contact information for all collaborators — names and institutions are sufficient. This information helps the program office identify potential reviewer conflicts of interest before the review panel is assembled.
Funding Opportunity Reference. Include the FOA number (e.g., PA-26-001, RFA-CA-26-012) and full title. This ensures that when program staff receives your LOI by email or through their submission system, it is matched to the correct competition.
Project Abstract (250 words or fewer). A concise description of the proposed project: what you plan to do, why it matters, and what the key innovation or approach is. This is not the place for extensive background or preliminary data. The abstract should convey the general scientific or programmatic direction so reviewers with the relevant expertise can be identified. Write it clearly enough that a program staff member who is not a specialist in your area can understand what the project is about.
Budget Estimate (if requested). Some programs ask for a rough order-of-magnitude budget estimate in the LOI. This is not a formal budget — a round number for total direct costs over the full project period is sufficient. If the FOA does not specifically ask for budget information, do not include it in the LOI.
Do not submit supporting documents, preliminary data, CVs, or letters of support with a federal LOI unless the NOFO specifically requests them. The LOI should be concise — typically one to two pages. Including unsolicited attachments suggests unfamiliarity with the process and may create administrative handling problems for the program office. Save your full scientific narrative, supporting data, and documentation for the complete application package.
LOI vs Letter of Inquiry (Foundation Context)
The acronym LOI is used for two very different documents in the grant world, and confusing them is a common mistake for organizations that work across both federal and private foundation funding.
In the federal grant context, a Letter of Intent is a non-binding administrative notice of your plan to apply. It does not require agency approval, does not constitute an early screening of your project, and does not influence the merit review of your full application. You submit it, the agency acknowledges receipt (or not), and you proceed with developing your full application regardless of any response.
In the private foundation context, a Letter of Inquiry (also abbreviated LOI) is a genuine pre-application step through which the foundation screens for fit before inviting full proposals. Foundations receive far more potential applicants than they can review at full proposal stage, so the LOI serves as the filtering mechanism. A foundation LOI typically runs 2 to 5 pages and includes a more substantive description of the proposed project, the organization's background, and the amount of funding sought. The foundation's program staff reviews LOIs and selects which organizations to invite for full proposals. If your LOI does not generate an invitation, you cannot proceed with that foundation in that grant cycle.
The practical consequences of this distinction are significant. In the federal process, submitting the LOI is a brief administrative step that takes 30 to 60 minutes to complete. In the foundation process, the LOI is your first competitive document and warrants the same careful strategic attention as a full proposal. An organization that invests only 30 minutes in a foundation LOI because they think it is "just a notice of intent" is likely to produce a weak document that does not generate an invitation.
The distinction also matters in the other direction: organizations accustomed to foundation LOIs who apply for their first federal grant sometimes assume the federal LOI requires similar depth and invest hours drafting a scientific narrative for what should be a brief administrative notification. This mismatch in effort is unnecessary — the federal LOI does not require and is not improved by extended scientific content.
Does the LOI Affect Review?
In the standard federal competitive grant process, the LOI does not affect merit review — period. This is worth stating clearly because it is a source of persistent confusion and unnecessary anxiety among applicants.
The merit review of a federal grant application is conducted by an independent review panel (a study section at NIH, a review panel at NSF, or an expert panel at other agencies). These reviewers receive the complete application package after the submission deadline and score it according to the published evaluation criteria. They do not receive the LOI, do not know whether an LOI was submitted, and are not influenced by any content in it.
Program staff — who are separate from the review panel — do see LOIs. Their role is administrative: confirming that the proposed project falls within the scope of the program, identifying potential reviewer conflicts based on names of personnel and institutions, and planning reviewer assignments. If a program officer has concerns about scope based on the LOI abstract, they may reach out to discuss — but this is an informational contact, not a pre-review scoring event.
The one situation where the LOI does have a direct effect: if submission of an LOI is a required condition of application eligibility and you fail to submit one by the deadline, your application may be returned without review. This is the exception rather than the rule, but it is why checking the NOFO for LOI requirements is non-optional in your application planning process.
Late LOI submissions — submitting after the stated due date but before the application deadline — rarely result in disqualification in programs where the LOI is not required. Program staff may note the late submission but will typically accept it for planning purposes. However, late LOIs may complicate reviewer recruitment if the program office has already assembled its review panel. The earlier you submit the LOI, the more useful it is for the agency's planning process — which is the only reason they requested it in the first place.
Writing a Strong LOI: Template and Tips
Given that the LOI is a brief administrative document, "strong" in this context means clear, complete, and appropriately concise — not scientifically impressive or persuasive. The goal is to give the program office the information it needs without padding, overreach, or scientific detail that belongs in the full application.
A standard federal LOI format that works across most programs:
Subject line / Header: "Letter of Intent — [FOA Number] — [Program Title]"
Paragraph 1 — Declaration of intent: "We intend to submit an application in response to [FOA Number], [FOA Title]. The proposed project is titled '[Working Project Title].'"
Paragraph 2 — Principal Investigator: State the PI's full name, degree, title, institution, department, address, phone, and email. If there are co-investigators or co-PIs at other institutions, list them by name and institution.
Paragraph 3 — Project Abstract (250 words): A clear, jargon-minimized description of what you propose to do, why it matters, and what approach you will use. Write for a well-educated generalist reader, not exclusively for a specialist reviewer. Avoid acronyms and technical shorthand that require deep domain knowledge to interpret.
Paragraph 4 — Participating institutions: List all institutions with significant roles in the proposed project and a one-sentence description of their contribution (e.g., "Massachusetts General Hospital will serve as a clinical data collection site.").
Closing line: "We plan to submit a complete application by [application deadline date]."
Practical tips for efficient LOI development: draft the project abstract first, as it is the only content that requires substantive thought. Everything else is contact and administrative information that can be assembled in minutes. Use your institution's grants and contracts office to confirm the submission method — some institutions have internal processes for LOI review before external submission. Maintain a record of your LOI submission (confirmation email, sent email copy) in case any questions arise later about your eligibility to submit a full application.
For NIH LOIs submitted by email (the most common method for many programs): send to the Scientific/Research Contact email address listed in the NOFO, using the FOA number in the subject line, and request a read receipt or confirmation. Keep the email body brief — many program offices receive dozens of LOI emails per competition cycle and appreciate concision. The LOI content can be in the body of the email or attached as a PDF depending on the NOFO's specified submission format.
Frequently Asked Questions
It depends on the specific funding opportunity. Many NIH FOAs request a non-binding LOI approximately 30 days before the application deadline. Some make it optional but encouraged; a smaller number require it as a condition of submission. Always check Section IV of the specific NOFO. If the FOA is silent on LOI, none is required or expected.
A standard federal LOI includes: the proposed project title; PI name, institution, and contact information; names of key collaborators and their institutions; the FOA number and title; and a concise project abstract (250 words or fewer). Some programs ask for a rough budget estimate. Do not include CVs, supporting data, or attachments unless the NOFO specifically requests them.
In the vast majority of federal programs, no. The LOI is an administrative planning document — reviewers never see it and it does not influence merit scoring. The exception is programs where LOI submission is a required eligibility condition: in those cases, not submitting by the deadline may result in your application being returned without review. Check the NOFO to confirm whether the LOI is required or optional.
Most federal grant LOIs are 1 to 2 pages. NIH LOIs are often submitted as an email or through an online form with character-limited fields. Unless the NOFO specifies a longer format, keep the LOI concise — its purpose is administrative notification, not scientific advocacy. A longer LOI does not improve your chances and may signal unfamiliarity with the program's conventions.
A federal grant Letter of Intent (LOI) notifies the agency you plan to apply — it is non-binding and does not require agency approval before you proceed. A foundation Letter of Inquiry (also LOI) is a pre-application screening step where the foundation reviews your concept and decides whether to invite a full proposal. In the foundation context, a positive response is typically required before you may submit a full application. The federal LOI requires about 30–60 minutes to prepare; the foundation LOI warrants the same attention as a full proposal.
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This article was researched and written by the GrantMetric editorial team using primary sources: official federal Notice of Funding Opportunity (NOFO) documents, the Code of Federal Regulations (CFR), OMB Uniform Guidance (2 CFR Part 200), agency budget justifications, and direct data from the Grants.gov API. Program details — funding amounts, eligibility criteria, deadlines — are cross-referenced against the issuing agency's official website before publication.
Editorial Notice: This article was reviewed by the GrantMetric editorial team. Federal grant programs change frequently — funding amounts, eligibility, and deadlines are subject to annual appropriations. To report an inaccuracy, contact dev@grantmetric.com.