How does the scope of ex parte reexamination differ from inter partes review?

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 scope of ex parte reexamination is more limited compared to inter partes review (IPR). Key differences include:

• Prior Art: Ex parte reexamination is limited to patents and printed publications, while IPR can consider a broader range of prior art.
• Grounds: Ex parte reexamination is based on 35 U.S.C. 102 and 103, while IPR can also include other grounds like 35 U.S.C. 101.
• Participation: In ex parte reexamination, third-party participation is limited after filing, while IPR allows ongoing third-party involvement.

According to MPEP 2258:

“The reexamination proceeding will be conducted in accordance with 35 U.S.C. 305 and 37 CFR 1.550.”

This emphasizes the more structured and limited nature of ex parte reexamination compared to the broader scope of IPR proceedings.