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.
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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?
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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?
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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?
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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?
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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?
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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
