Key Takeaways
- Expect increased scrutiny under §§ 102, 103, and 112 as § 101 rejections become less common for well-drafted AI and software applications.
- U.S. patent attorneys should consider treating Desjardins as the operative playbook for AI and software eligibility: (1) identify a technical problem, (2) disclose a technical solution/improvement in detail, and (3) draft claims that implement that solution/improvement.
- U.S. patent attorneys should broaden their claim formats to cover eligible types of AI model improvements and corresponding patent eligible subject matter, and should take additional care to ensure that patent applications intended to be filed overseas still provide express support for specific technical applications and architectures when applicable.
- Non-U.S. patent attorneys and agents drafting priority-establishing patent applications outside the U.S. should keep in mind that the U.S. currently permits a broader scope of protection than perhaps their domestic territories permit and should consider including appropriate claim formats for use in the U.S.
- An improvement to an AI model per se is not likely to be deemed patentable subject matter at the EPO unless it is specifically tied to a type of technical effect deemed acceptable in EPO case law.
Introduction to Desjardins
The USPTO’s recent decision in Ex parte Desjardins has marked a significant shift in the legal precedent for patent eligibility under 35 U.S.C. § 101, particularly in the context of AI and software innovations. On November 4, 2025, the USPTO designated the Appeals Review Panel (ARP) decision as precedential, overturning the Patent Trial and Appeal Board’s (Board) earlier rejection of claims directed to training a machine learning model. The ARP held that such claims are patent-eligible when they integrate a mathematical concept into a practical application that improves how the model operates.
The Desjardins Decision
The claims in question recite a computer-implemented method of training a machine learning model on a first task, determining importance measures for parameters, and then training the model on a second task while adjusting parameters to optimize performance. Although both the ARP and the Board agreed that the mathematical calculation recites an abstract idea, the ARP disagreed with the Board’s conclusion that no additional elements integrate the judicial exception into a practical application. The ARP relied on Enfish, which recognizes that software can make non-abstract improvements to computer technology, and found that the specification identified technological improvements, including the ability to effectively learn new tasks in succession while protecting knowledge about previous tasks.
Implications of Desjardins
The USPTO has moved quickly to implement Desjardins, issuing updates to the MPEP on December 5, 2025, which instruct examiners to evaluate the specification for a detailed, non-conclusory disclosure of a technological improvement and confirm that the claim reflects that improvement. Examiners must avoid overgeneralizing or dismissing limitations as "generic computer components" when they confer technical improvement. The MPEP now treats improved machine learning training that preserves prior knowledge as an example of improvement in computer functionality. This decision establishes a practical path for AI and software eligibility, where claims that integrate a mathematical concept into a practical application that improves how the model operates are likely to be deemed patent-eligible.
Practical Applications of Desjardins
Desjardins signals an adjustment in practice in favor of AI and software eligibility at the USPTO. Practitioners should expect more consistent credit for technical improvements in AI and software. However, examiners will likely scrutinize whether claims truly reflect the disclosed improvement and whether the specification’s assertions are sufficiently detailed rather than conclusory. The debate is shifting to §§ 102, 103, and 112, which will likely require practitioners to build a solid record to overcome these traditional hurdles from the start. U.S. patent attorneys should consider treating Desjardins as the operative playbook for AI and software eligibility, identifying a technical problem, disclosing a technical solution/improvement in detail, and drafting claims that implement that solution/improvement.
Global Implications of Desjardins
Non-U.S. patent attorneys and agents drafting priority-establishing patent applications outside the U.S. should keep in mind that the U.S. currently permits a broader scope of protection than perhaps their domestic territories permit. An improvement to an AI model per se is not likely to be deemed patentable subject matter at the EPO unless it is specifically tied to a type of technical effect deemed acceptable in EPO case law. Typically, this requires the model to be limited to an application in a technical field, or alternatively, the model would need to be adapted to a particular technical implementation. It is recommended to seek advice on the specifics from a suitably specialized patent attorney.
The Appeals Review Panel and Precedential Designation
The USPTO established the Appeals Review Panel (ARP) on July 24, 2023, which may be convened by the Director to review decisions of the Board in ex parte appeals, re-examination appeals, and reissue appeals. The ARP’s routine decisions may be nominated after issuance for precedential designation, which is binding Board authority in subsequent matters involving similar facts or issues. The Director’s designation of Desjardins as precedential means that examiners must follow its reasoning in future cases, marking a significant shift in the legal precedent for patent eligibility under 35 U.S.C. § 101.