How does supplemental examination differ from ex parte 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.

Supplemental examination differs from ex parte reexamination in several key aspects:

• Information scope: Supplemental examination allows consideration of any information relevant to the patent, while ex parte reexamination is limited to patents and printed publications.
• Grounds of patentability: Supplemental examination can involve any ground of patentability, including subject matter eligibility, novelty, obviousness, written description, enablement, indefiniteness, and double-patenting.
• Initiation: Only patent owners can request supplemental examination, whereas ex parte reexamination can be requested by anyone.

The MPEP notes: “Unlike ex parte reexamination practice, the information that the patent owner may request to be considered, reconsidered, or corrected in a supplemental examination proceeding is not limited to patents and printed publications.”