Where should ex parte reexamination requests be mailed?

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.

Ex parte reexamination requests should be mailed to a specific address at the USPTO. According to MPEP 2226, mail related to ex parte reexamination should be marked as follows:

“Mail Stop Ex Parte Reexam”

This special marking ensures that the mail is directed to the appropriate office for initial processing. It’s important for patent attorneys and applicants to use this correct mailing address to avoid delays in processing their ex parte reexamination requests.