How does the USPTO treat claims held “not invalid” by a federal court in 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.

The USPTO may still reexamine claims that have been held “not invalid” by a federal court. According to MPEP § 2259:

“Claims finally held as ‘not invalid’ by a federal court, after all appeals, may still be subject to reexamination.”

This means that even if a court has upheld the validity of certain claims, the USPTO retains the authority to reexamine those claims. The MPEP further references the case In re Construction Equipment Company, stating:

“The majority did not adopt the dissent view that reexamination of claims finally held as ‘not invalid’ by a federal court was barred by claim preclusion (res judicata) or issue preclusion (collateral estoppel).”

This underscores the USPTO’s position that court decisions upholding claim validity do not prevent the Office from conducting its own reexamination of those claims.