Patent inventorship turns on one thing: who conceived the claimed invention. Not who paid for it, not who managed the project, not who did the bench work, and not whose name is on the company. Conception is the touchstone, and the law measures it claim by claim rather than product by product.
This is the most commonly botched fact in a patent application, and it is not cosmetic. Inventorship is decided by federal law, not by a company’s internal politics or a lab’s authorship customs. Get it wrong deliberately and the patent can be held unenforceable for inequitable conduct. Get it wrong and leave out a real inventor, and that person may retain an undivided ownership share that lets them license your patent to your competitor without asking you.
Conception is the formation in the inventor’s mind of a definite and permanent idea of the complete and operative invention, as it is thereafter to be applied in practice. The Federal Circuit set out the standard in Burroughs Wellcome Co. v. Barr Laboratories (1994): the idea must be specific enough that a person of ordinary skill could reduce it to practice without extensive research or further inventive effort.
Two consequences follow, and both surprise people.
First, a vague goal is not conception. “We should make a battery that charges in five minutes” is a wish. The particular electrode chemistry that gets you there is the invention. Whoever articulated that chemistry conceived it, even if they never touched a lab bench.
Second, reduction to practice is not conception. The technician who built the prototype, ran the assay, or wrote the code from a detailed spec contributed labor, not conception, and is not an inventor on that basis. Burroughs Wellcome held exactly this: the outside researchers who confirmed that AZT worked against HIV had performed the confirmatory testing, but the conception was already complete before their tubes were run.
The list of people who feel like inventors but are not is long, and it is where most disputes start:
The mirror-image error matters just as much. Leaving out someone who did conceive a claimed feature, in order to keep the list tidy or to freeze out a departing colleague, is the version courts treat harshly when it is deliberate.
Section 116 of the Patent Act is short and does a lot of work. Joint inventors may apply together even though they did not physically work together or at the same time, did not each make the same type or amount of contribution, and did not each contribute to the subject matter of every claim.
Read that last clause carefully. A person who conceived the single feature recited in dependent claim 12, and nothing else in the document, is a joint inventor of the entire patent. There is no such thing as being an inventor of part of a patent. Inventorship attaches to the document.
The Federal Circuit’s test in Pannu v. Iolab Corp. (1998) asks whether the person contributed in some significant manner to conception, made a contribution that is not insignificant in quality when measured against the full invention, and did more than merely explain well-known concepts or the current state of the art. Dana-Farber Cancer Institute v. Ono Pharmaceutical Co. (Fed. Cir. 2020) added the collaboration point with force: the collaboration can be loose, the contributors need not have appreciated where the work was heading, and a joint inventor does not lose that status merely because the eventual patentee did most of the work.
These are separate questions and conflating them causes expensive accidents.
Inventorship is a fact: who conceived it. Ownership is title: who holds the property. Under U.S. law, rights vest initially in the inventor, and they move to anyone else only by a written assignment. That default is stubborn. In Board of Trustees of the Leland Stanford Junior University v. Roche Molecular Systems (2011), the Supreme Court held that the Bayh-Dole Act does not automatically vest title to federally funded inventions in the contracting university. Stanford lost because a researcher had signed a present assignment to Cetus (“I hereby assign”) after signing only a promise to assign to Stanford (“I agree to assign”). The present-tense grant took effect immediately; the promise created only an obligation. Four words of verb tense moved title to a competitor.
The stakes on the ownership side are set by section 262. Absent an agreement, each co-owner of a patent may make, use, sell, and license the invention without the consent of the others and without accounting to them for profits. Ethicon, Inc. v. United States Surgical Corp. (Fed. Cir. 1998) drove the point home: an omitted inventor was added to the patent, which made him a co-owner, and he had already licensed the accused infringer and refused to join the suit as a plaintiff. Because all co-owners must join as plaintiffs in an infringement action, the case was dismissed. One forgotten inventor ended it.
Errors are correctable, and the standard is forgiving of honest mistakes. Section 256 allows the USPTO or a district court to correct inventorship on an issued patent when a person is named in error or omitted in error, and the patent is not invalid on that ground if the error is correctable. Section 116 provides the parallel route for a pending application.
The historic requirement that the error be free of deceptive intent was removed by the America Invents Act for patents in this posture, which broadened the fix considerably. What remains fatal is fraud: deliberately naming or omitting inventors to deceive the examiner can support an inequitable conduct defense that renders the whole patent unenforceable, which is a worse outcome than any single invalid claim.
Note also that inventorship follows the claims, and claims change during prosecution. If amendments cancel the only claims that a named inventor contributed to, that person is no longer an inventor and the list must be corrected. Inventorship should be re-checked at allowance, not settled once at filing.
In Thaler v. Vidal (Fed. Cir. 2022), the applicant named an AI system called DABUS as the sole inventor. The Federal Circuit affirmed the rejection on statutory text alone: the Patent Act defines an inventor as an “individual,” and the Supreme Court has read “individual” in statutes to mean a natural person. No policy debate was needed. The Supreme Court denied certiorari in 2023.
USPTO inventorship guidance fills in the practical rest, and it has moved. The February 2024 guidance, which ran AI-assisted inventions through the Pannu factors, was rescinded in its entirety and replaced by revised guidance published November 28, 2025. The revised guidance applies one standard to all inventions: there is no separate or modified test for AI-assisted inventions, and the question stays what it always was, whether a natural person conceived the claimed invention, meaning a specific and settled solution rather than a general goal or research plan. The Pannu factors still matter, but only where two or more natural persons might be joint inventors. They do not apply to a lone human working with an AI tool, because a machine cannot be a joint inventor and there is no joint inventorship question to analyze. Prompting a system with a general problem is still not enough. Contributing to the design, training, or particular use of the system in a way that shapes the specific claimed solution can be. The machine is never named.
Who counts as an inventor on a patent? Whoever conceived the claimed invention. Conception means forming a definite and permanent idea of the complete and operative invention, specific enough that a skilled person could build it without further inventive work. People who funded the project, supervised it, ran experiments to someone else’s instructions, or supplied ordinary materials are not inventors, no matter how essential their contribution was in practice.
What is joint inventorship under 35 U.S.C. 116? Two or more people are joint inventors if they collaborated in some fashion and each contributed something significant to the conception of at least one claim. Section 116 says they need not work physically together, at the same time, make the same type or amount of contribution, or contribute to every claim. A person who conceived a feature recited only in claim 12 is a joint inventor of the whole patent.
What is the difference between inventorship and ownership? Inventorship is a factual question about who conceived the invention. Ownership is a property question about who holds title. Inventors own their invention initially, and title moves only by a written assignment. In Stanford v. Roche (2011) the Supreme Court held that even federally funded research does not vest title in the university by operation of law, so an employer with sloppy assignment paperwork can own nothing.
Can an AI system be named as an inventor? Not in the United States. In Thaler v. Vidal (Fed. Cir. 2022) the court held that the Patent Act’s use of the word individual means a natural person, so an AI system cannot be listed as an inventor. Revised USPTO guidance published November 28, 2025, which rescinded the earlier February 2024 guidance, confirms that AI-assisted inventions remain patentable so long as a natural person conceived the claimed invention, judged by the same standard as any other invention, but the machine itself is never named.
Going further: Invention Assignment Agreements, and how ownership actually transfers .
This page is general legal information, not legal advice, and it does not create an attorney-client relationship.
The Federal Circuit's conception standard: inventorship fixes when the idea is definite and permanent, so NIH scientists confirming AZT were not co-inventors.
The Federal Circuit added two collaborators as co-inventors of Nobel-backed cancer-immunotherapy patents; contribution to conception need not span every claim.
The Federal Circuit removed a claimed co-inventor from Hormel's precooked-bacon patent, holding that a contribution mentioned only in passing was too insignificant to confer joint inventorship under the Pannu test.
The Federal Circuit held that the Patent Act's word 'individual' means a human being, so an AI system called DABUS cannot be listed as an inventor, without deciding whether AI-assisted inventions are patentable at all.
A 5-4 Supreme Court preserved assignor estoppel but confined it to cases where an inventor's invalidity attack contradicts a representation made in assigning the patent.
The Federal Circuit set out the durable standard for joint inventorship and confirmed that misjoinder or nonjoinder is not automatic invalidity, because the patentee must be given a chance to correct under Section 256.
A co-inventor of even a single claim becomes a co-owner of the whole patent. The Federal Circuit let that overlooked inventor license the accused infringer and dismantle the case.
The Supreme Court held that the Bayh-Dole Act does not automatically vest patent rights in a federally funded university. Title still begins with the inventor, and a stray 'do hereby assign' can send it elsewhere.
