Patent Reexamination Process Patent Reassessment Patent Reevaluation Patent Reexamination Patent Review The Patent Reexamination Process allows the U.S. Patent and Trademark Office (USPTO) to re-evaluate the validity of an existing patent based on new evidence or prior art not considered during the original examination. This process can be requested by the patent owner or a third party and aims to confirm the patent's claims or cancel them if they are found to be invalid.