What is the standard for granting an inter partes 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.

The standard for granting an inter partes reexamination request depends on when the request was filed:

• For requests filed prior to September 16, 2011: A substantial new question of patentability must be raised.
• For requests filed on or after September 16, 2011: There must be a reasonable likelihood that the requester will prevail with respect to at least one challenged claim.

The MPEP states:

“It is only necessary to establish that a substantial new question of patentability or reasonable likelihood that requester will prevail exists as to one of the patent claims in order to grant reexamination.”

It’s important to note that the determination is made without input from the patent owner and does not involve a final decision on patentability.