If you want to count or compare AI patents — the work this desk does constantly — you cannot search by vibes. You search by CPC, the Cooperative Patent Classification system that every examiner uses to file a patent into the right technical bucket. For AI, three branches do most of the work, and knowing them turns a hopeless keyword search into a precise one.
Start with G06N — "computing arrangements based on specific computational models." This is the heart of machine-learning IP. The neural-network subtree, G06N 3/04 and its children (G06N 3/045, G06N 3/08, G06N 3/0495, and so on), is where you find the architecture patents. Google's foundational mixture-of-experts grant US10719761B2 is classified G06N 3/0454 and G06N 3/08; Microsoft's perplexity-routing grant US12547872B2 sits in G06N 3/042, G06N 3/08, and G06N 3/0495. When people say "AI patent," they usually mean something in G06N.
Next, G06F — electric digital data processing. This is where method-and-system patents live when the claimed contribution is about computing infrastructure, data handling, or retrieval rather than the network itself. Google's search-feedback fine-tuning grant US12437016B2 is classified G06F 16/9538 and G06F 40/20 — note it is not in G06N at all, even though it is unmistakably an AI training method. That is a trap for keyword searchers and a reason to read the classifications, not the buzzwords.
Third, G06V — image or video recognition. This is the vision and multimodal branch, and it has surged with the rise of vision-language models. Salesforce's vision-language pretraining grant US12462592B2 carries G06V 20/70 and G06V 10/764; NVIDIA's data-augmentation grant US12651480B2 sits in G06V 10/774 and G06V 10/82. Anthropic's computer-use agent grant US12619815B2 spans G06V and G06N and G06F — eighteen CPC codes in total, which is exactly what you expect from a multimodal agent that perceives, reasons, and acts.
That last point is the one to internalize: real AI patents are rarely single-class. The classification list is a fingerprint of what the invention touches. A grant in G06N 3/045 plus G06V 10/82 is telling you "neural architecture, applied to vision." One in G06F 16/9538 plus G06F 40/20 is telling you "retrieval, applied to language." Read the codes together and the patent's actual subject matter resolves before you read a single claim.
So the practical answer to "what class are AI patents filed under?" is: usually G06N, frequently alongside G06F or G06V, and you should always check all of them. The codes are how you find the IP — and, just as importantly, how you avoid missing the AI patents that hide outside G06N.