How does inherency apply to anticipation rejections in patent examination?

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.

Inherency is an important concept in anticipation rejections under 35 U.S.C. 102. It allows examiners to consider features that are not explicitly stated in a prior art reference but are necessarily present or naturally flow from the reference’s teachings. The MPEP 2131 states:

“To serve as an anticipation when the reference is silent about the asserted inherent characteristic, such gap in the reference may be filled with recourse to extrinsic evidence. Such evidence must make clear that the missing descriptive matter is necessarily present in the thing described in the reference, and that it would be so recognized by persons of ordinary skill.”

Key points about inherency in anticipation rejections include:

• The inherent feature must be necessarily present, not just probably or possibly present.
• Extrinsic evidence can be used to show that a feature is inherent, but the evidence must clearly demonstrate that the feature is always present in the prior art.
• The inherent feature must be recognized by persons of ordinary skill in the art.
• Inherency cannot be based on what would result from optimization of the prior art or from combining the teachings of multiple references.

Examiners must carefully consider inherency arguments and ensure they meet these criteria when applying anticipation rejections based on inherent features.