What is the significance of the term “aggregation” in patent law?

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 term “aggregation” in patent law refers to a historical concept that is no longer considered a valid basis for rejecting patent claims. According to MPEP 2173.05(k):

“A claim should not be rejected on the ground of ‘aggregation.’”

This guidance reflects a shift in patent examination practice. Historically, “aggregation” was used to describe claims that combined elements without producing a new or unexpected result. However, modern patent law and practice focus on more specific statutory grounds for rejection, such as novelty, non-obviousness, and clarity of claims.

The cases of In re Gustafson and In re Collier established that rejections based on aggregation are non-statutory and that applicants are entitled to know the specific statutory basis for any rejection (e.g., under 35 U.S.C. 101, 102, 103, or 112).