An other transaction is a legally binding agreement the Defense Department may use to buy research, prototypes and follow-on production outside most federal procurement law, including the Federal Acquisition Regulation. DoD obligated more than $18 billion through them in fiscal 2024, up from $1.8 billion in fiscal 2016, according to a Government Accountability Office report published Sept. 3, 2025.
That growth is the central fact of the mechanism. Other transactions, universally shortened to OTs or OTAs in the trade, began as a narrow research instrument and now carry a share of Pentagon development spending large enough that Congress and GAO both argue DoD cannot fully account for where the money goes.
What follows is how the authority actually works: the statutes, the eligibility conditions a program office has to satisfy, the approval tiers by dollar value, and the follow-on production path that makes a prototype award commercially interesting to a company that has never held a defense contract.
What is an other transaction agreement?
An other transaction is a contract that is not a procurement contract. It binds both parties, but it is exempt from the body of statute and regulation that governs standard federal buying — the Federal Acquisition Regulation (FAR, the rulebook that sets clauses, cost principles and data rights for conventional contracts), the cost accounting standards, and much of the associated audit apparatus.
Two authorities matter. Under 10 U.S.C. § 4021, DoD may use OTs for basic, applied and advanced research projects. Under 10 U.S.C. § 4022, it may use them for prototype projects and, under specified conditions, for follow-on production.
The Defense Acquisition University, DoD's own training body, frames the point of the instrument as access rather than savings: OTs, it says, "may reduce barriers to entry associated with traditional procurement contracts" and give the government a route to "innovative technologies, commercial practices, nontraditional defense contractors, small businesses, nonprofit research institutions, and traditional defense contractors." That is DAU's characterization of the tool's purpose, not an assessment of whether it delivers.
The practical consequence for industry is that terms are negotiated rather than inherited. Intellectual property, milestone payments, financing and audit rights are written into the agreement itself, which is why the instrument appeals to firms whose commercial business would not survive full cost accounting standards coverage.
Which conditions must a prototype OT meet?
Section 4022(d)(1) requires that at least one of four conditions be satisfied before a prototype OT can be used. A program office does not get to choose the instrument on convenience grounds alone; it has to land on one of these.
- At least one nontraditional defense contractor or nonprofit research institution participates "to a significant extent" in the prototype project.
- All significant participants other than the federal government are small businesses or nontraditional defense contractors.
- At least one third of the total cost of the prototype project is paid from funds provided by sources other than the federal government.
- The senior procurement executive determines in writing that exceptional circumstances justify a transaction providing for innovative business arrangements or structures.
Condition three is the cost-share route traditional primes use when no nontraditional participant is available. Condition four is the escape hatch, and it requires a signature at the service's senior procurement executive level rather than at the program office.
What counts as a nontraditional defense contractor?
The definition is narrower than the phrase suggests and it is mechanical, not cultural. Under 10 U.S.C. § 3014, a nontraditional defense contractor is an entity that is not currently performing, and has not performed for at least the one-year period preceding the solicitation, any DoD contract or subcontract subject to full coverage under the cost accounting standards.
Two things follow. First, the test is about accounting-system exposure, not company size, age or sector — a large commercial firm with no recent CAS-covered defense work qualifies. Second, status is losable and regainable: a company that completes a CAS-covered contract and then stays out of that category for a year can return to nontraditional status.
That mechanical quality is what makes the category contested in oversight terms. Congress writes eligibility conditions around a label that measures a firm's accounting history rather than its distance from the traditional industrial base.
Who has to approve an OT, and at what dollar value?
Approval authority rises in two steps written directly into § 4022(a)(2). Below $100 million, a prototype OT proceeds on the contracting activity's normal authority. Above that, the statute imposes named signatures and, at the top tier, advance notice to Congress.
| Expected DoD cost, including all options | Statutory approval requirement |
|---|---|
| Up to $100,000,000 | No additional statutory determination specified in § 4022(a)(2) |
| Over $100,000,000, not over $500,000,000 | Written determination by the head of the contracting activity that the requirements are met and that use of the authority is essential |
| Over $500,000,000 | Written determination by the agency's senior procurement executive that use of the authority "is essential to meet critical national security objectives," plus written notice to the congressional defense committees at least 30 days in advance |
The thresholds are cumulative and option-inclusive, which is the detail most often missed in industry summaries: the test is what the project is expected to cost DoD including all options, not the value of the initial obligation.
How does a prototype become production without a new competition?
This is the commercial heart of the authority. Section 4022(f)(2) permits a follow-on production contract or transaction to be awarded to the prototype participants without further competitive procedures if competitive procedures were used to award the prototype OT and the participants successfully completed the prototype project.
In other words, the competition happens once, at the prototype stage, and a company that finishes the work has a statutory path into production without re-competing. For a firm weighing whether to build a defense line of business, that is the difference between a one-off development award and a program of record.
GAO's September 2025 review put fiscal 2024 prototype OT obligations at more than $16 billion and production OT obligations at $2 billion. The gap between those two figures is the practical measure of how much of the OT portfolio has actually crossed into production versus how much remains in development.
What does Congress still not know about OT spending?
GAO's finding is about visibility, not legality. The report concluded that data gaps limit DoD's ability to assess how well OTs are working, and recommended that the department systematically track standard contracts that result from prototype OTs and improve reporting accuracy for consortium-based awards. DoD agreed with both; GAO listed the recommendations as open as of publication.
Consortia are the specific blind spot. A Congressional Research Service primer dated Dec. 19, 2024 reports that roughly half of DoD's OT obligations are awarded to consortia, and that per DoD's contract policy director approximately 80 percent of OTs fund research and development, with the remainder covering weapons and ammunition, electronic and communication equipment, and professional services.
The same primer records the scale of the shift: DoD OT actions rose from 496 in fiscal 2017 to 4,391 in fiscal 2022. Existing oversight consists of quarterly reports to the House and Senate Appropriations Committees and annual reports to Congress on prototype OT use.
Legislative pressure has followed the money. DefenseScoop reported on Aug. 2, 2024 that Sen. Catherine Cortez Masto, D-Nev., introduced a bill requiring the undersecretary of defense for acquisition and sustainment to run a roughly five-year pilot tracking OTA awards, including "the number and amounts awarded to small businesses and nontraditional defense contractors" and consortium-based awards, with a final briefing to the armed services committees due by Sept. 30, 2029. The status of that legislation as of this writing is not established by the sources here.
What does this mean for a company evaluating the route?
The instrument rewards firms that can meet a nontraditional test, tolerate negotiated rather than standardized terms, and finish a prototype cleanly enough to trigger the follow-on path. It does not remove the government's need for a documented competition at the prototype stage, and it does not make the eventual production award automatic.
It also carries an oversight trajectory. An authority that grew tenfold in obligations between fiscal 2016 and fiscal 2024 while GAO twice flagged data gaps is an authority Congress is likely to keep legislating against. What the terms will look like in five years is unknown; the Defense Acquisition University guidance and the statute are the two documents that define them today.
For a related business news perspective, read How the Pentagon Uses Other Transaction Agreements to Skip the FAR.