What is the time limit for filing a rebuttal brief in an inter partes 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.

According to MPEP 2678, the time limit for filing a rebuttal brief in an inter partes reexamination is one month from the mailing date of the examiner’s answer. This is specified in 37 CFR 41.66(d), which states:

“Any appellant may file a rebuttal brief under § 41.71 within one month of the date of the examiner’s answer. The time for filing a rebuttal brief or an amended rebuttal brief may not be extended.“

It’s important to note that this one-month period is strict and cannot be extended.