What happens if multiple applications for extension are filed for the same patent?

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.

If multiple applications for extension are filed for the same patent, the USPTO will issue the certificate of extension based on the first filed application. According to 37 CFR 1.785(a):

“If more than one application for extension of the same patent is filed, the certificate of extension of patent term, if appropriate, will be issued based upon the first filed application for extension.”

This ensures that only one extension is granted per patent, even if multiple applications are submitted.