Direct comparison
SBIR vs. STTR: Key Differences
STTR requires a formal small-business/nonprofit-research partnership with fixed work-share minimums; SBIR does not. Compare eligibility and NIH mechanics.
Ask about SBIR vs. STTR: Key Differences
Answers are drawn from this comparison and the rest of the CASRAI corpus, with a link to every source.
Answers are AI-generated from CASRAI’s own published pages and can be wrong, so check the linked sources before relying on one; your question is logged without personal data — never sold, never used to train a third-party model — to show us what CASRAI is missing, so please do not type personal or confidential details. How we use this
How do SBIR, STTR compare side by side?
The table below compares SBIR, STTR across 17 procurement-relevant dimensions, from full name through reauthorization status (2026).
Side-by-side comparison
| Dimension | SBIR | STTR |
|---|---|---|
| Full name | Small Business Innovation Research | Small Business Technology Transfer |
| Established | 1982 (Small Business Innovation Development Act, P.L. 97-219) | 1992 (Small Business Technology Transfer Act) |
| Research-institution partnership | Optional (voluntary subcontract) | Mandatory, formally documented, every funded phase |
| Small-business work-share minimum | 2/3 (66.7%) in Phase I; 1/2 (50%) in Phase II | At least 40% (fixed minimum, both phases) |
| Research-institution work-share minimum | No minimum -- purely discretionary | At least 30% (fixed minimum, both phases) |
| PI employment | Must be primarily employed by the small business | May be employed by either the small business or the research institution |
| Prime awardee | Small business (university cannot be prime) | Small business (university cannot be prime) |
| Eligibility floor | U.S. for-profit, >50% owned by U.S. citizens/permanent residents, <500 employees including affiliates | Same eligibility floor, plus a qualifying U.S. nonprofit research institution partner |
| Participating agencies | 11 agencies | 5 of those 11 (DoD, HHS/NIH, DOE, NASA, NSF) |
| NIH activity codes | R43 (Phase I), R44 (Phase II) | R41 (Phase I), R42 (Phase II) |
| NIH-only application tracks | Direct-to-Phase-II and Phase IIB bridge awards available | Not available -- Phase I, Phase II, or Fast-Track only |
| Statutory set-aside minimum | At least 3.2% of qualifying extramural R&D budget | At least 0.45% of qualifying extramural R&D budget (higher agency-budget threshold applies) |
| Phases | I (feasibility), II (full R&D), III (commercialization, separately funded) | Same three-phase structure |
| Typical Phase I / Phase II award size | Government-wide statutory guideline ceiling: Phase I up to $323,090; Phase II up to $2,153,927 | Same government-wide statutory guideline ceiling as SBIR |
| IP / licensing implications | No government ownership stake; if commercializing university IP, still requires a separate license/option agreement under Bayh-Dole | Same IP treatment as SBIR; the research institution's own contribution can itself generate patentable IP subject to Bayh-Dole |
| Funding type | Non-dilutive (grant/cooperative agreement/contract) | Non-dilutive (grant/cooperative agreement/contract) |
| Reauthorization status (2026) | Reauthorized through Sept. 30, 2031 (S. 3971) | Reauthorized through Sept. 30, 2031 (S. 3971), same act |
Common questions
Common questions about SBIR vs STTR
Can a small business choose either SBIR or STTR for the same project?
+
Not freely. A proposal without a formal research-institution partnership must go through SBIR. A proposal built around such a partnership generally applies through STTR at agencies that offer it -- the two are not interchangeable wrappers around identical eligibility.
Does a voluntary university subcontract under SBIR count as an STTR-style partnership?
+
No. An SBIR subcontract is a business choice with no fixed work-share guarantee, no formal partnership documentation requirement, and none of STTR's PI-employment flexibility.
Is STTR always better for a university than SBIR?
+
Not necessarily. STTR guarantees the university a protected role and budget share, but only 5 agencies offer it, and some faculty founders prefer the flexibility of an SBIR subcontract without a fixed percentage. Agency fit and how much work the university genuinely needs to perform both matter.
Do SBIR and STTR have different funding caps?
+
The two programs largely share the same statutory guideline ceilings; differences are usually agency-specific solicitation choices rather than a difference built into the statutes themselves. Check the current agency solicitation for exact figures.
What's the difference between SBIR and STTR at NIH specifically?
+
The core distinctions apply the same way at NIH as elsewhere. NIH adds separate activity codes (R43/R44 for SBIR, R41/R42 for STTR), a shared Omnibus Solicitation plus Institute-specific announcements, and two SBIR-only tracks -- Direct-to-Phase-II and Phase IIB -- unavailable to STTR applicants.
Going deeper
