SBIR vs. STTR: Which Program Should You Apply To?

A biotech startup spun out of a university lab has a promising drug delivery platform, two co-founders with faculty appointments, and a first patent filed through the university's tech transfer office. They are ready to apply for federal R&D funding. The question that trips up companies like this every cycle: SBIR or STTR?

Both programs fund early-stage technology development through the same 11 federal agencies, use the same Phase I and Phase II structure, and offer comparable award amounts. But the rules governing who does the work, where the principal investigator sits, and how intellectual property flows differ in ways that can determine whether your application is even eligible, let alone competitive.

The Core Structural Difference: Work Percentages

The SBIR program is built around the principle that the small business performs the primary research. In Phase I, the company must perform at least two-thirds (67%) of the work. In Phase II, that threshold drops to at least one-half (50%). You can subcontract to universities, national labs, or other organizations, but the company leads and executes the majority of the project.

STTR flips this balance to require meaningful participation from a nonprofit research institution, typically a university. The minimum work allocation is 40% for the small business and 30% for the research institution, with the remaining 30% flexible between the two. This is not a subcontracting relationship. STTR mandates a formal Cooperative Research and Development Agreement (CRADA) between the company and the institution that spells out intellectual property rights, publication rights, and each party's responsibilities.

The practical effect: if your technology was developed entirely in-house and your R&D team can execute the proposed work, SBIR gives you maximum control. If your technology depends on university facilities, faculty expertise, or institutional capabilities that you cannot replicate internally, STTR provides the legal framework to make that partnership work within a federal award.

Principal Investigator Rules: Where Your PI Sits

This is where many first-time applicants get caught. Under SBIR, the principal investigator must be primarily employed by the small business at the time of award. A faculty member who consults for your company on weekends does not qualify. The PI needs to be on your payroll, with the company as their primary employer during the project period.

STTR has no such restriction. The PI can be employed by either the small business or the partnering research institution. This is a critical distinction for university spinouts where the core inventor is still a tenured professor. Under STTR, that professor can serve as PI while maintaining their faculty position. Under SBIR, you would need a different PI, which may weaken the application if the professor is the leading expert on the technology.

Some companies work around this by having the faculty member take a leave of absence or shift to majority employment at the company during the award period. It works, but it introduces complications around tenure, benefits, and university policies that STTR avoids entirely.

Navigating Agency Topics: SBIR-Only, STTR-Only, and Both

Not every solicitation topic is available under both programs. Agencies designate individual topics as SBIR-only, STTR-only, or open to both. The Department of Defense, the largest SBIR/STTR funder, publishes hundreds of topics per cycle, and the SBIR/STTR designation varies by topic based on the research area and the agency's priorities.

Before committing to either program, check whether your target topic accepts applications under both. If a topic you want is SBIR-only and your PI is university-employed, you have a structural problem that no amount of proposal writing can fix. Conversely, some research-heavy topics are STTR-only because the agency specifically wants university involvement, and applying under SBIR for a similar topic at a different agency may not capture the same funding priority.

The complete SBIR application guide walks through how to read solicitation topics and identify which program designation applies. Reviewing the current SBIR eligibility rules under the 2026 reauthorization is also essential, as several ownership and affiliation requirements have been updated.

When to Apply to Both Programs Simultaneously

There is no rule against applying to both SBIR and STTR in the same cycle, as long as you are submitting to different agencies or different topics. Many companies do exactly this, especially when their technology has applications across multiple agency missions.

A common pattern: submit an STTR Phase I at the agency where your university partner has the strongest relationships (often NIH or NSF), while simultaneously submitting an SBIR Phase I at a different agency where the company can execute independently (often DoD or DOE). If both are awarded, you run parallel projects with different scopes. If only one wins, you have still entered the SBIR/STTR ecosystem and can build from there.

Another strategic approach is starting with STTR in Phase I, when the research is closer to the university lab, then transitioning to SBIR for Phase II, when the work shifts toward product development and the company takes a larger role. This is permitted as long as you meet each program's work percentage requirements at each phase. The Phase II solicitation will specify whether SBIR, STTR, or both are accepted.

The Cooperative R&D Agreement: What STTR Requires That SBIR Does Not

The CRADA requirement is the most underestimated part of STTR applications. This is not a boilerplate document. It must address intellectual property allocation between the company and the institution, define each party's scope of work, and establish how disputes will be resolved. Many universities have template CRADAs through their Office of Sponsored Research, but negotiating the IP terms can take weeks or months.

Start the CRADA conversation early. University tech transfer offices move on their own timeline, and a CRADA that is still being negotiated when your proposal is due will weaken your submission. Reviewers want to see a signed or near-final agreement that demonstrates both parties are committed and have resolved the key IP questions.

For SBIR applications, subcontracting to a university is simpler. You issue a subcontract, the university performs defined tasks, and IP ownership typically stays with the company per the federal funding agreement. The trade-off is that the university's role must remain within the work percentage limits, which constrains how much of the project they can perform.

Making the Decision

The choice between SBIR and STTR usually comes down to three questions. Where was the core technology developed? Where does the principal investigator work? And how much of the project depends on institutional resources you cannot replicate internally?

If your technology was built inside your company, your PI is on staff, and you can execute the research plan with limited outside help, SBIR is the cleaner path. If your technology came from a university lab, your lead researcher is still faculty, or the project requires specialized institutional facilities, STTR provides the structure to make that collaboration fundable.

Either way, understanding the mechanical differences between these programs before you start writing prevents the kind of eligibility mistakes that sink otherwise strong proposals, and Granted can help you identify which open solicitations across all 11 agencies match your technology and team structure.