A practical guide to NSF and NIH grants, what each agency funds, who is eligible, how the application and review process works, and tips for a competitive proposal.

The National Science Foundation (NSF) and the National Institutes of Health (NIH) are the two largest sources of research funding in the United States. For research institutions, universities, and science-focused nonprofits, they are also among the most demanding funders to navigate.

NSF and NIH grants are not like foundation grants. They run on specialized application formats, expert peer review, and timelines measured in many months. Applicants who treat them like an ordinary foundation proposal lose. Applicants who understand how these agencies actually work are competitive.

This guide explains what NSF and NIH fund, who’s eligible, how their processes work, and how to put together a competitive proposal.

TL;DR: Quick Answers

What’s the difference between NSF and NIH? The NSF funds fundamental research across science and engineering broadly. The NIH funds biomedical, health, and behavioral research.
Who can apply? Primarily universities, research institutions, and qualifying nonprofits, applications are submitted by an institution on behalf of a principal investigator (PI).
How are proposals reviewed? By expert peer-review panels (NIH “study sections,” NSF review panels) scoring against published criteria.
How long does it take? A long process, often six months to a year or more from submission to award. Plan well ahead with a grants calendar.

NSF vs. NIH: What Each Funds

Both are federal agencies, so both behave like federal grants: rigorous, competitive, compliance-intensive. But their subject focus differs.

The NSF supports fundamental research and education across nearly all non-medical fields of science and engineering, physics, biology, computer science, mathematics, the geosciences, engineering, the social and behavioral sciences, and STEM education. NSF review famously weighs two criteria: intellectual merit (the quality and importance of the research) and broader impacts (the project’s benefit to society).

The NIH supports biomedical, clinical, behavioral, and public-health research, work aimed at understanding health and disease and improving human health. NIH funding is organized across multiple institutes and centers, each focused on particular diseases or research areas.

A simple rule of thumb: if the research is about human health and disease, it likely belongs at the NIH; most other science and engineering research belongs at the NSF. Some areas overlap, and identifying the right agency, and the right program or institute within it, is itself an act of funder research.

NIH & NSF by the Numbers

The scale of these two agencies is worth understanding before you apply, because it shapes how competitive the process is.

NIH is the largest public funder of biomedical research in the world, with an appropriation near $48 billion. Per NIH RePORT figures, NIH awarded roughly $35.3 billion in competing and noncompeting grants in FY2025, out of a $48.5 billion appropriation. The agency makes more than 60,000 grants a year, supporting over 300,000 researchers at 2,500-plus institutions, and it is organized into 27 institutes and centers, each with its own appropriation and priorities.

The competition is stiff, and getting stiffer. NIH’s overall research project success rate was around 13% in 2025 (NIH RePORT). For early-stage investigators, the R01-equivalent success rate fell from 29.8% in FY2023 to 18.5% in FY2025. A newer NIH multiyear funding policy is shifting the agency toward fewer but larger grants: the FY2026 request would fund 4,312 new competing grants, down 29.3% from FY2025’s 6,095. For how these odds compare across programs, see our grant success rate statistics.

The return on that spending is well documented: NIH estimates that every $1 of NIH funding generated about $2.46 in economic activity in FY2023.

NSF is smaller but still enormous. On a roughly $9.9 billion FY2024 budget, NSF funded more than 11,000 new awards. In FY2023, NSF evaluated 38,340 proposals and made 11,056 new awards (NSF / NCSES), which puts the average funding rate for many programs in the low-to-mid 20s percent. Specific NSF programs vary widely: the NSF Graduate Research Fellowship totals about $159,000 per fellow ($37,000/year stipend plus $16,000 cost-of-education allowance over three years), with a success rate around 16–17%, while NSF CAREER early-career awards fund at roughly 15–25% depending on directorate.

If your work is a fit for small-business R&D, note that both agencies also run SBIR/STTR programs, see our SBIR & STTR grants guide.

Who Is Eligible

NSF and NIH grants are usually institutional. The applicant of record is an organization, a university, a research institute, sometimes a research-capable nonprofit or small business, not an individual. The research itself is led by a principal investigator (PI), but the institution submits and is accountable.

This means:

Your organization needs the infrastructure to apply: federal registrations (SAM.gov, Grants.gov, and agency-specific systems), and the financial and compliance systems to manage a federal award and its reporting.
Smaller nonprofits without a research office may struggle here, or may participate as a partner or subawardee on a larger institution’s grant.
Specific programs (early-career awards, small-business research programs like SBIR/STTR, training grants) carry their own eligibility rules. Always read the specific funding opportunity announcement.

How the Application and Review Process Works

Both agencies use expert peer review, and understanding it is the key to writing competitively.

At the NIH, applications are typically reviewed by a study section, a panel of scientists in the relevant field, who evaluate and score the application against defined criteria (significance, investigators, innovation, approach, environment). Scored applications then go to an institute’s advisory council for funding decisions. The NIH uses standardized activity codes (the well-known R01 is its flagship research project grant; others support smaller projects, early-career researchers, and training).

At the NSF, proposals are reviewed by panels and/or external reviewers who assess intellectual merit and broader impacts, with a program officer guiding funding recommendations.

Two consequences for applicants:

Your audience is expert peers. You’re writing for scientists who know the field, the literature, and the methods. The proposal must be rigorous and precise, not simplified.
The process is long. Between submission, review, council, and award, six months to a year or more is normal. NSF and NIH grants must be planned far in advance, and resubmission after a first rejection is common and expected. See how long it takes to get a grant.

Tips for a Competitive NSF or NIH Proposal

Read the specific funding opportunity in full. NSF and NIH publish detailed solicitations and announcements with exact requirements, page limits, and formats. Compliance is enforced strictly, see how to read a grant RFP.
Address the review criteria directly. Write to significance, innovation, and approach (NIH) or intellectual merit and broader impacts (NSF). Reviewers score against these, so make each one easy to find and easy to score well.
Make the specific aims or project summary outstanding. The NIH Specific Aims page and the NSF project summary are read first and disproportionately shape reviewer impressions. Invest heavily in them.
Show rigor and feasibility. Reviewers must believe the research design is sound and that you can actually do it. A clear approach and realistic plan matter as much as a bold idea.
Build a precise budget. Federal research budgets are detailed, including personnel effort, equipment, and indirect (F&A) costs. See how to build a grant proposal budget.
Plan for resubmission. A strong proposal rejected on the first try is normal. Use reviewer feedback and resubmit, persistence is part of the strategy.
Note AI-use guidance. Federal research agencies have issued guidance on the use of AI in preparing and reviewing applications. Check the current policy and follow it, see can funders tell if a grant was written by AI.

How Grantboost Helps With Research Funding

NSF and NIH proposals demand scientific rigor, that part is irreducibly the PI’s expertise. But a great deal of the surrounding work, structuring the proposal to the solicitation, drafting the organizational and broader-impacts sections, keeping language consistent, and managing the long timeline, is exactly where Grantboost helps.

Grantboost learns your institution and past proposals, so recurring sections draft in your organization’s established voice. It structures proposals around the specific funding opportunity’s requirements. It keeps the long federal timeline, with its many sub-deadlines, organized in one pipeline and calendar. And its continuous discovery surfaces relevant solicitations across agencies, plus complementary foundation research funding, so federal grants sit inside a balanced funding strategy.

Try Grantboost free and spend more time on the science, less on the paperwork.

NSF & NIH Grants: A Guide to Federal Research Funding