How does the USPTO determine if a claim is directed to a law of nature or natural phenomenon?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

The USPTO uses a two-step analysis to determine if a claim is directed to a law of nature or natural phenomenon. This process is outlined in MPEP Section 2106.04(b):

1. Step 2A, Prong One: Examiners evaluate whether the claim recites a law of nature or natural phenomenon.
2. Step 2A, Prong Two: If the claim recites an exception, examiners determine whether the claim integrates the exception into a practical application.

The MPEP states:

“Even if a claim does recite a law of nature or natural phenomenon, it may still be eligible at any of Pathways A through C.”

This means that even if a claim recites a law of nature or natural phenomenon, it may still be patent-eligible if it applies the exception in a practical way or adds significantly more to the exception.

For products of nature, examiners use a markedly different characteristics analysis to evaluate nature-based product limitations and determine eligibility.