— GLOSSARY

Every NIH acronym that trips up first-time applicants — in plain English.

NOFO, NOSI, JIT, RPPR, MPI, SRO, Payline, ESI, UEI. If you have asked what a term means twice, it is on this page.

— APPLICATION TYPES

A0 / A1: A0 is the original submission of an application; A1 is the single permitted resubmission. NIH no longer allows A2.
FOAFunding Opportunity Announcement: The prior term for what NIH now calls a NOFO. Still widely used in day-to-day speech.
Modular vs Detailed Budget: Modular = $25K increments up to $250K direct/year, minimal detail (domestic R01-family). Detailed = line-item budget required above $250K direct/year or on SBIR/STTR, foreign, and most non-R01 mechanisms.
NOFONotice of Funding Opportunity: The current NIH term for a funding opportunity announcement. Section IV of the NOFO overrides the Application Guide for that opportunity.
NOSINotice of Special Interest: A short notice that signals NIH interest in a research area and points to one or more existing parent NOFOs to apply through. NOSIs do not accept applications directly.
PAProgram Announcement: A standing NOFO that invites applications in a broad area. Usually reviewed in standard study sections against standard due dates.
PARProgram Announcement with Special Review: A PA where NIH conducts the peer review in a special study section rather than the standard CSR panels.
PASProgram Announcement with Set-Aside funds: A PA where an Institute has committed dedicated funds to award applications submitted in response.
PHS 398: The Public Health Service form set — Research Plan, Biosketch, Human Subjects, etc. — that layers on top of the SF424 for NIH.
RFARequest for Applications: A time-limited NOFO with dedicated funds and, usually, a single receipt date. Reviewed in a special study section convened by the sponsoring IC.
SF424: The government-wide grant application form set used on Grants.gov. Every NIH application starts as an SF424 (R&R) package.

— REVIEW & SCORING

Council: An IC's Advisory Council. Second-level review that recommends applications for funding after study section — meets three times a year.
Impact Score: The Overall Impact score assigned by the study section: 10–90, lower is better. Only applications discussed at the meeting receive one.
Not Discussed / ND: An application in the bottom half of the study section's queue is not discussed at the meeting and receives no Overall Impact score — only the assigned reviewers' preliminary criterion scores and critiques.
Payline: An IC's conservative funding cutoff — the percentile or score at which applications are essentially guaranteed to be funded. Published annually by IC; not all ICs use one.
Percentile: Where an application's impact score falls relative to a rolling base of scored applications in the same study section. Used by many ICs to set funding decisions.
SRGScientific Review Group: Formal name for a study section.
Streamlined / Triage: The process by which the SRO removes bottom-half applications from discussion. 'Streamlined' and 'triaged' mean the same thing as 'Not Discussed'.
Study Section: A standing or ad hoc panel of scientists convened by CSR (or an IC) to peer-review applications. Also called a Scientific Review Group (SRG).

— ROLES & PEOPLE

ESIEarly Stage Investigator: A PI within 10 years of their terminal research degree or clinical training who has not previously served as PI on a substantial NIH research grant. ESI status can trigger favorable funding decisions.
GMS / GMOGrants Management Specialist / Officer: IC business-side contact who handles Just-in-Time, budget negotiation, Notice of Award, and post-award compliance.
MPI / Multi-PI: An application with multiple PD/PIs, each holding equal formal responsibility for the project. Requires a Leadership Plan attachment.
NINew Investigator: A PI who has not previously competed successfully for a substantial NIH research grant. All ESIs are NIs; not all NIs are ESIs.
PI / PDPrincipal Investigator / Project Director: The scientific lead of the project. On SBIRs, the Contact PD/PI must be primarily employed (>50%) by the small business; on STTRs, they need not be an employee.
POProgram Officer: The IC scientific-portfolio contact for your application. Advises on fit before submission, on responsiveness to critiques after review, and on funding likelihood before Council.
SOSigning Official: The person at your organization authorized in eRA Commons to submit applications and sign binding documents on the organization's behalf.
SROScientific Review Officer: The NIH staff scientist who runs a study section — assigns reviewers, manages the meeting, releases summary statements. Not a voting member.

— POST-AWARD

ICInstitute or Center: One of NIH's 27 Institutes and Centers; 24 of them award grants. Each IC sets its own priorities, paylines, and SBIR waiver topics.
JITJust-in-Time: The post-review request from NIH for updated information — Other Support, IRB/IACUC approvals, current budget — before award. Triggered when your score is likely to fund; does not mean you are funded.
RCDCResearch, Condition, and Disease Categorization: The automated NIH system that tags each funded project with disease and research categories for public reporting. RCDC categories power the disease-area filters on RePORTER and Winner Intelligence.
RPPRResearch Performance Progress Report: The annual and final progress report all NIH grantees submit. Late RPPRs delay the next year's funding.

— SBIR/STTR

Commercialization Plan: Required attachment on Phase II / D2P2 SBIR and STTR applications. Up to 12 pages. Covers market, competition, IP, team, financing, and revenue path — not a scientific document.
De Minimis: The safe-harbor indirect rate under 2 CFR 200 that any entity without a negotiated federal rate may elect. Currently 15% of modified total direct costs.
Direct Costs: Costs directly attributable to the project: salaries, materials, contracts, equipment, travel. What appears on the line-item budget.
Direct-to-Phase-II (D2P2): An SBIR-only route (R44) that skips Phase I. Requires prior non-SBIR funding demonstrating the equivalent of Phase I feasibility.
Fast-Track: A combined Phase I + Phase II application reviewed and (if funded) awarded together. Cuts the gap between phases; requires strong Phase I preliminary data at submission.
Fee: SBA-recognized fixed allowance of up to 7% of total costs (direct + indirect) on SBIR/STTR awards. Distinct from indirect costs; not audited as profit.
Indirect Costs (F&A)Facilities & Administrative: Overhead: rent, utilities, admin salaries, general office. Recovered via a negotiated rate or the de minimis rate below.
Phase I: Feasibility phase. R43 (SBIR) / R41 (STTR). Typically 6–12 months; cap varies by IC under the 2026 parent solicitations (commonly up to $400K, and up to $700K at several ICs under the 2026 parent solicitations).
Phase II: Full R&D phase. R44 (SBIR) / R42 (STTR). Typically 2 years; up to $2.5M–$3M under the 2026 parent solicitations. Requires the Commercialization Plan attachment.
Phase IIB / CRPCommercialization Readiness Pilot: Post-Phase II funding to close the commercialization gap — regulatory work, manufacturing scale-up, clinical validation. Structure and cap vary by IC.
SBCSmall Business Concern: The legal designation the applicant must qualify as: for-profit, ≤ 500 employees (including affiliates), majority-owned by US individuals or eligible investment entities, and meeting the SBA ownership tests.
SBIRSmall Business Innovation Research: Congressionally mandated federal program that sets aside R&D funding for US small businesses. NIH is the largest non-DoD SBIR funder.
STTRSmall Business Technology Transfer: Sibling program to SBIR that requires formal partnership with a non-profit research institution. At least 40% of the work is performed by the small business and at least 30% by the institution.

— REGISTRATIONS & FORMS

DUNS: Retired. Formerly the government-wide organization identifier issued by Dun & Bradstreet. Replaced by the UEI in April 2022 — legacy references only.
eRA Commons: NIH's grants portal. Every PD/PI, Signing Official, and administrator on an application needs an eRA Commons account, and the organization must be registered.
Grants.gov: The federal cross-agency portal through which SF424 applications are submitted. NIH validates the package after Grants.gov accepts it — a Grants.gov 'accepted' is not a successful NIH submission.
SAM.gov: The System for Award Management. Every applicant organization must be actively registered here to receive any federal award. Renew annually.
SBA Company Registry: The SBA-run registry that SBIR/STTR applicants must complete before submission. Generates a certificate that must be uploaded with the SBIR/STTR Information form.
UEIUnique Entity Identifier: The 12-character alphanumeric identifier SAM.gov assigns to your organization. Replaced DUNS as the government-wide identifier in April 2022.

Definitions on this page are written for plain-language use by first-time applicants. For the authoritative NIH glossary, see the NIH Grants Glossary.