What happens to amendments if a patent expires during 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.

If a patent expires during reexamination:

• All amendments to the patent claims and all claims added during the proceeding are withdrawn.
• The patent owner is notified in the next Office action.
• All subsequent reexamination will be on the basis of the unamended patent claims.
• No amendments, other than claim cancellations, will be incorporated into the patent by a certificate issued after expiration.

The MPEP clearly states: “Pursuant to 37 CFR 1.530(j), ‘[n]o amendment may be proposed for entry in an expired patent.’ Thus, if a patent expires during the pendency of a reexamination proceeding for a patent, all amendments to the patent claims and all claims added during the proceeding are withdrawn.” This policy ensures that expired patents are not modified through reexamination.