Can amendments be made to an expired patent during reexamination?
No, amendments cannot be made to an expired patent during reexamination. The MPEP clearly states:
If the patent expires during the reexamination procedure, and the patent claims have been amended, the Office will hold the amendments as being improper and all subsequent reexamination will be on the basis of the unamended patent claims.
This policy is based on 37 CFR 1.530(j), which states: No amendment may be proposed for entry in an expired patent. Moreover, no amendment, other than the cancellation of claims, will be incorporated into the patent by a certificate issued after the expiration of the patent.
It’s important for patent owners to be aware of their patent’s expiration date and to complete any desired amendments before that date.
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