Patent eligibility

Section 101 contains an important implicit exception: laws of nature, natural phenomena and abstract ideas are not patentable². The Court has described a two-step framework for telling claims to those concepts from claims to patent-eligible applications of them^2,3.

1. Is the claim directed to a judicial exception?First, determine whether the claims at issue are directed to one of those patent-ineligible concepts². The MPEP describes the judicial exceptions as limited to abstract ideas, laws of nature and natural phenomena, including products of nature⁴.
2. Is there an inventive concept?If so, ask what else is there in the claims. Consider the elements of each claim both individually and as an ordered combination to determine whether the additional elements transform the nature of the claim into a patent-eligible application. The Court describes this as a search for an inventive concept².
3. Generic implementation is not enoughThe mere recitation of a generic computer cannot transform a patent-ineligible abstract idea into a patent-eligible invention². In Mayo, a patent had to do more than simply state the law of nature while adding the words apply it, and steps that added only well-understood, routine, conventional activity previously engaged in by those in the field were not enough³.

The Court has also emphasized that an invention is not ineligible simply because it involves a judicial exception, and that integrating an abstract idea, law of nature or natural phenomenon into a practical application may be eligible, according to the MPEP's reading of the cases⁴.

MPEP 2106 sets two criteria. First, the claimed invention must be to one of four statutory categories: processes, machines, manufactures and compositions of matter. Second, the claim must not be directed to a judicial exception unless the claim as a whole includes additional limitations amounting to significantly more than the exception⁴. The MPEP says the Alice/Mayo two-part test is the only test that should be used to evaluate eligibility of claims under examination. The machine-or-transformation test is considered as part of the integration or significantly more determinations, not as a separate test⁴.

The USPTO's current MPEP is the Ninth Edition, Revision 01.2024, which does not incorporate changes made after January 31, 2024, and the USPTO lists later notices that supersede parts of it⁵. For eligibility these include the July 2024 Guidance Update on subject matter eligibility, including artificial intelligence, an August 4, 2025 memorandum on evaluating eligibility, and memoranda of December 4, 2025 and April 30, 2026 on Rule 132 subject matter eligibility declarations¹². The notices also include the advance notice of 5 December 2025 on Ex parte Desjardins, an Appeals Review Panel decision designated precedential on 4 November 2025. The notice revises MPEP 2106.04(d), 2106.05(a) and 2106.05(f), says its updates are not intended to announce any new USPTO practice or procedure, and tells examiners to consider existing precedent such as Enfish, particularly for machine learning and artificial intelligence claims. It says Desjardins analyzed eligibility in terms of whether the claims were directed to an improvement in the functioning of a computer, or to an improvement to other technology or a technical field, under Federal Circuit precedent in Enfish and McRO⁶. Under revised MPEP 2106.04(d)(1), when an examiner considers whether a claim improves the functioning of a computer or another technology, the specification need not state the improvement explicitly but must describe the invention so that the improvement would be apparent to a person of ordinary skill in the art. A conclusory assertion of improvement is not enough. The claim must then reflect the disclosed improvement by including the components or steps that provide it, though it need not recite the improvement itself⁶.

In Association for Molecular Pathology v. Myriad Genetics (2013) the Supreme Court held that a naturally occurring DNA segment is a product of nature and not patent eligible merely because it has been isolated, but that cDNA is patent eligible because it is not naturally occurring⁸. See Gene patent.

European patents are granted for any inventions, in all fields of technology, provided they are new, involve an inventive step and are susceptible of industrial application (Article 52(1) EPC). Article 52(2) says the following in particular are not regarded as inventions: discoveries, scientific theories and mathematical methods; aesthetic creations; schemes, rules and methods for performing mental acts, playing games or doing business, and programs for computers; and presentations of information. Under Article 52(3), the exclusion applies only to the extent the application or patent relates to such subject-matter or activities as such⁷.

Article 53 EPC adds exceptions to patentability: inventions whose commercial exploitation would be contrary to ordre public or morality; plant or animal varieties and essentially biological processes for the production of plants or animals; and methods for treatment of the human or animal body by surgery or therapy and diagnostic methods practised on the human or animal body¹¹.

The EPO Guidelines (2026 edition, G-II, 3.6) say computer programs are excluded from patentability if claimed as such, but the exclusion does not apply to computer programs with technical character. To have it, a program must produce a further technical effect going beyond the normal physical interactions between the program and the computer it runs on⁹. The Guidelines add that claims to a computer-implemented method, a computer-readable storage medium or a device cannot be objected to under Article 52(2) and (3), because methods using technical means, and technical means themselves, have technical character. Novelty and inventive step are then assessed⁹.

In decision G 1/19 of 10 March 2021 the Enlarged Board of Appeal held that a computer-implemented simulation of a technical system or process, claimed as such, can for the purpose of assessing inventive step solve a technical problem by producing a technical effect going beyond the simulation's implementation on a computer. It is not sufficient that the simulation is based, in whole or in part, on the technical principles underlying the simulated system or process¹⁰.

A Supreme Court decision shows the two-step test applied to computer-implemented claims².

The Court held that the claims at issue were drawn to the abstract idea of intermediated settlement, and that merely requiring generic computer implementation fails to transform that abstract idea into a patent-eligible invention. It affirmed the judgment of the Federal Circuit2.