What is a “reexamination of a reexamination”?

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.

A “reexamination of a reexamination” refers to a situation where a new reexamination request is filed on a patent for which a reexamination certificate has already been issued, or when a reexamination certificate is issued on a prior reexamination while a new reexamination is pending. As stated in MPEP § 2695:

“This reexamination request is generally referred to as a ‘reexamination of a reexamination.’”

This process allows for multiple rounds of reexamination on the same patent, ensuring continued scrutiny of patent validity.