USPTO Issues Memorandum Reminding Examiners Regarding Subject Matter Eligibility Evaluation

Deputy Commissioner for Patents Charles Kim issued a memorandum to three technology centers reminding examiners how subject matter eligibility should be evaluated under 35 USC § 101. These technology centers often handle inventions directed to artificial intelligence and machine learning, and claims for those inventions are frequently rejected as lacking patent eligibility.

On August 4, 2025, Kim issued the memorandum to Technology Centers 2100, 2600, and 3600. While expressly stating that it is “not intended to announce any new USPTO practice or procedure,” the five-page memo provides a timely reminder of key considerations when assessing subject matter eligibility under Section 101.

KEY TAKEAWAYS

Step 2A Prong One: ‘Recites’ vs. ‘Involves’ a Judicial Exception

The memo bridges guidance provided in the earlier examples 37-42 with the more recent examples 47-49, refuting any misconceptions that the more recent examples have somehow superseded the earlier ones.

The memo reaffirmed that

“training the neural network in a first stage using the first training set” of example 39 does not recite a judicial exception, whereas

“training, by the computer, the ANN based on the input data and a selected training algorithm to generate a trained ANN, wherein the selected training algorithm includes a backpropagation algorithm and a gradient descent algorithm,” in claim 2 of example 47 recites a judicial exception due to the express reference to mathematical calculations by name.

The Mental Process Grouping Is Not Without Limits

Examiners are also cautioned against overextending the “mental process” category of abstract ideas as the grouping does not include “claim limitations that cannot practically be performed in the human mind.”

Step 2A Prong Two: Improvements Consideration

A claim is eligible at Step 2A Prong Two when the claim covers a particular solution to a problem or a particular way to achieve a desired outcome, as opposed to merely claiming the idea of a solution or outcome.

Reiterates That Neither the Claim Nor the Specification Needs to Explicitly Set Forth the Improvement 

While MPEP at 2106.04(d)(1) already expressly states that the specification need not explicitly set forth the improvement, examiners that do not follow such an approach would benefit from the memo’s timely reminder.

Cautions Against the ‘Apply It’ Pitfall

The memo cautions examiners not to oversimplify claim limitations and to consider whether the claim invokes computers or other machinery merely as a tool to perform an existing process.

It is unclear whether this guidance is consistent with the ex parte appeal outcomes at the Patent Trial and Appeal Board. A search at PTAB Open Data using the provided filters for the 50 most recent ex parte appeal decisions involving applications from the 3600 Technology Center (July 17–August 12, 2025) having only § 101 rejections (presumably the lack of prior art rejections indicates that the claims are not directed to an existing process) shows that only a single case was reversed, and the examiners were affirmed in 46 other cases, with three cases being reversed with a new ground of rejection. It will be interesting to see if the memo changes the appeals outcome at the PTAB.

Close Calls Require Caution

Examiners should only issue Section 101 rejections if there is a more than 50% probability that the claim is ineligible. Uncertainty alone is insufficient.

IMPLICATIONS FOR INNOVATORS

The memo reinforces the importance of drafting a specification that supports AI/ML claims that demonstrates how the claims do not simply invoke computers or other machinery merely as a tool to perform an existing process, are not directed to automating an abstract idea, and do not simply apply generic machine learning to new data environments.

Ideally, the specification should sufficiently describe technological improvements and various implementation details such that the improvement would be apparent to one of ordinary skill in the art.

Patent applicants should work closely with counsel to ensure claims are framed and the specification is drafted to withstand Section 101 scrutiny, particularly in light of evolving AI-related examination practices.