SBIR vs STTR: Differences, Eligibility, and Which Program Is Right for You (2026)

If you have started reading about federal R&D programs for small businesses, you have probably seen SBIR and STTR mentioned in the same breath. They look similar on the surface, same three phases, same dollar caps, same sbir.gov portal, but the eligibility rules and strategic fit are different enough that picking the wrong one can cost a year of runway.

This guide breaks down SBIR vs STTR end-to-end: what each program is, who runs it, who qualifies, how the funding stacks up, and how to decide which one is right for your company. If you are brand new to either program, start with our pillar guide on what SBIR is and come back here.

Quick Answer: SBIR vs STTR

SBIR and STTR are both federal R&D programs that fund American small businesses through the same three-phase structure with the same Phase I and Phase II dollar caps. The decisive differences: SBIR runs at 11 federal agencies and requires no research partner, while STTR runs at only 5 agencies and mandates a formal partnership with a U.S. research institution performing at least 30% of the work. SBIR is roughly 7x larger by total funding (~$3.7B/yr vs ~$555M/yr as of 2024). Pick STTR when the technology is spun out of a university lab or relies on academic facilities; pick SBIR when the small business can perform the work itself.

SBIR and STTR at a Glance

The fastest way to understand the two programs is to put them side-by-side.

The funding caps and three-phase structure are identical. Almost everything else, eligibility, partnership rules, agency mix, is different.

SBIR (Small Business Innovation Research): What It Is

SBIR is the federal government's flagship non-dilutive R&D funding program for small businesses. It was established in 1982 and is administered by the Small Business Administration (SBA), with awards made by 11 individual federal agencies.

The 11 SBIR-participating agencies are:

• Department of Defense (DoD): by far the largest funder; roughly half the program
• National Institutes of Health (NIH) (under HHS)
• National Science Foundation (NSF)
• Department of Energy (DOE)
• NASA
• Department of Homeland Security (DHS)
• Environmental Protection Agency (EPA)
• Department of Agriculture (USDA)
• Department of Commerce (DOC) (including NIST and NOAA)
• Department of Education (ED)
• Department of Transportation (DOT)

Every federal agency with more than $100 million in extramural R&D spending must set aside at least 3.2% of that budget for SBIR. In aggregate, that adds up to roughly $3.7 billion per year flowing to small American companies as of 2024.

SBIR awards have no equity dilution and are not loans; they are either grants (NIH, NSF, USDA, some DOE) or contracts (DoD, NASA, DHS, most others). For a deeper look, see our pillar on what SBIR is.

STTR (Small Business Technology Transfer): What It Is

STTR is SBIR's smaller, partnership-driven sibling. It was established in 1992 with a specific purpose: move research out of America's universities and federal laboratories and into the commercial marketplace through a small business intermediary.

STTR runs at only 5 federal agencies:

• Department of Defense (DoD)
• National Institutes of Health (NIH), under HHS
• National Science Foundation (NSF)
• Department of Energy (DOE)
• NASA

(These are the agencies with extramural R&D budgets above $1 billion, the threshold that triggers an STTR set-aside.)

The STTR set-aside is 0.45% of agency extramural R&D, much smaller than SBIR's 3.2%. Total annual STTR funding sits around $555 million as of 2024.

What makes STTR distinctive is the mandatory partnership. Every STTR application must include a formal agreement with a U.S. research institution, a university, federally funded R&D center (FFRDC), or qualifying nonprofit research organization. The partner must perform at least 30% of the work; the small business must perform at least 40%. The remaining 30% can go to either party or other subcontractors.

STTR was designed for cases where the technology is too early-stage or too academic for a small business to develop alone. If your company spun out of a university lab and your founding team includes a professor who still has a faculty appointment, STTR is often the natural fit.

Eligibility Differences in Detail

Both programs share a baseline eligibility checklist, then diverge on partnership and PI rules. Our SBIR eligibility requirements guide covers the full SBIR checklist; here is how STTR differs.

Shared eligibility (both SBIR and STTR)

• For-profit small business organized in the United States
• 500 or fewer employees, including affiliates
• At least 51% owned and controlled by U.S. citizens or permanent residents (with limited VC-ownership exceptions, agency-dependent)
• Work performed in the United States (with limited, pre-approved exceptions)
• Registered on SAM.gov, SBIR.gov, and the relevant agency portal (DSIP for DoD, eRA Commons for NIH, etc.), see our SAM.gov registration guide

SBIR-specific eligibility

• The Principal Investigator (PI) must be primarily employed by the small business at the time of award and through the project, typically defined as more than 50% of the PI's time spent at the company.

STTR-specific eligibility

• A formal partnership with a U.S. research institution (university, FFRDC, or qualifying nonprofit research org), documented in an Allocation of Rights Agreement.
• Work-share split: small business ≥40%, research institution ≥30%, remaining 30% allocated by agreement.
• The PI can be primarily employed by either the small business or the research institution. This is the single biggest practical difference: a tenured professor can serve as STTR PI without leaving their faculty appointment.

That last bullet is why STTR exists. Under SBIR, a professor cannot lead the project unless they switch their primary employment to the small business, a non-starter for most academics. STTR removes that barrier.

Funding and Phases (Phase I, II, and III)

Both programs use the same three-phase structure. The phase architecture is identical; only some agency-specific caps and durations vary.

A few details that trip up first-time applicants:

• The dollar caps shown above are the SBA-published statutory caps that apply across both SBIR and STTR. Some agencies (notably DoD and NIH) award higher dollar values for specific topics with an SBA waiver.
• Phase I award sizes vary by agency. NSF Phase I is typically ~$305,000; DoD Phase I often runs $250,000–$295,000; some DoD topics use a smaller "Phase I-Open" track at ~$50,000–$75,000.
• Phase II requires a successful Phase I as the on-ramp at most agencies, but some run a Direct-to-Phase-II track. We cover this in our SBIR Phase 1 vs Phase 2 guide.
• Phase III is where SBIR and STTR get unusual. Phase III is not funded by either program; it is any work that derives from Phase I or Phase II, funded by other sources (including federal sole-source contracts under FAR 6.302-5). There is no dollar cap and no competition required. This is the single most underused feature of both programs.

When to Choose SBIR vs STTR

There is no universally "better" program. The right choice depends on your team, technology, and target agency.

Choose SBIR if:

• Your small business has the technical capability to perform the majority of the work in-house
• Your PI works full-time at the company (or will switch their primary employment)
• Your target agency is one of the 6 SBIR-only agencies (DHS, EPA, USDA, DOC, ED, DOT). STTR isn't an option there
• You want the larger pool of money and don't need university lab access
• Speed matters. STTR's partnership negotiation can add 1–3 months to the proposal cycle

Choose STTR if:

• The core technology was developed in a university or federal lab
• Your PI is a professor who can't (or won't) leave their academic appointment
• You need access to specialized academic facilities (e.g., a clean room, a particle accelerator, a clinical population)
• Your small business team is small and the research institution will do real research, not just lend a name
• The agency you are targeting (DoD, NIH, NSF, DOE, NASA) participates in both, many founders apply to STTR specifically because it's a less-crowded queue at the same agency

In practice, many companies that started with STTR move to SBIR once they have built up internal staff. The two programs are not mutually exclusive: you can hold active SBIR and STTR awards at the same time, even at the same agency, as long as they are separate projects.

SBIR vs STTR FAQs

Can I apply for both SBIR and STTR?

Yes. A single small business can hold active SBIR and STTR awards simultaneously and even apply to both programs in the same solicitation cycle. What you cannot do is submit the same project to both programs at the same time. The work has to be substantively different.

Is STTR easier to win than SBIR?

Generally no. STTR has a smaller applicant pool, but the partnership requirement adds complexity, you have to negotiate an Allocation of Rights Agreement, manage two organizations, and explain the work-share split in the proposal. Win rates are roughly comparable to SBIR (15–25% at Phase I depending on agency).

Who owns the IP in STTR?

The small business owns the data rights on STTR-funded work, the same as SBIR. The Allocation of Rights Agreement between the small business and the research institution governs how background IP, foreground IP, and licensing royalties are split. Most universities have standard STTR IP templates, but the terms are negotiable. Our advice: hire counsel for this conversation. The IP terms set early can determine whether a Phase III commercialization is profitable years later.

What's the average SBIR or STTR success rate?

Phase I success rates vary by agency and topic but typically run 15–25%. Phase II success rates among Phase I awardees run 40–55%. The end-to-end conversion from "first proposal submitted" to "Phase II awarded" sits in the high single digits.

Does my STTR research-institution partner need to be a U.S. university?

It must be a U.S.-based non-profit research institution. Eligible categories: U.S. universities (public or private), domestic non-profit research organizations, and federally funded R&D centers (FFRDCs). Foreign universities cannot serve as the STTR research partner.

Does STTR count as past performance for federal contracts?

Yes. A successfully completed STTR Phase I or Phase II carries the same past-performance weight as SBIR. Combined with Phase III sole-source authority, both programs are credible entry points into federal contracting, see our broader guide on easiest government contracts to win.

Can VC-backed companies apply for STTR?

The same rules that apply to SBIR apply to STTR. Some agencies (notably NIH) allow majority VC-owned firms to compete; others (notably DoD) do not. The work-share, ownership, and U.S.-control rules are identical between the two programs.

Which program does my agency participate in?

The 5 STTR agencies are the agencies whose extramural R&D budgets exceed $1 billion. The other 6 SBIR agencies are below that threshold and are SBIR-only.

Bottom Line

SBIR and STTR look similar because they are similar, same dollar caps, same phases, same sbir.gov portal. The decisive difference is the mandatory research-institution partnership in STTR, which exists to make university spinouts and academic-led research feasible at small companies that otherwise couldn't pull it off.

If you are weighing the choice for the first time, our broader government contracting small business guide puts SBIR and STTR in context with the other federal small-business pathways. And the pillar on what SBIR is goes deeper on the funding mechanics, Phase III sole-source authority, and the application process, most of which apply to STTR identically.

For founders building a multi-year federal R&D strategy, the smart move is usually to map both programs against your target agency's topics and your team's structure, then pick the one that fits, not to assume the bigger pool of money is automatically the better fit. STTR's smaller queue and academic flexibility are real advantages for the right team.