Can examiners consider prior art not cited in the reexamination request?

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.

Yes, examiners are not limited to the prior art cited in the reexamination request. According to MPEP 2244:

“The examiner is not limited in making the determination based on the patents and printed publications relied on in the request. The examiner can find ‘a substantial new question of patentability’ based upon the prior art patents or printed publications relied on in the request, a combination of the prior art relied on in the request and other prior art found elsewhere, or based entirely on different patents or printed publications.”

This gives examiners flexibility in considering a wide range of prior art when determining if a substantial new question of patentability exists.