Can collateral estoppel apply in patent reexamination proceedings?

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.

Collateral estoppel, or issue preclusion, can apply in certain circumstances during patent reexamination proceedings. According to MPEP § 2259:

“If the claims in a reexamination proceeding present the same issue(s) as claims that were finally held invalid by a federal court in a proceeding involving a different patent in the same patent family, collateral estoppel may apply if the patentee had a full and fair opportunity to litigate that issue in federal court.”

However, collateral estoppel generally cannot be applied against the USPTO based on a district court holding in an infringement proceeding. The MPEP cites the case In re Trans Texas Holdings Corp., where the court held that:

“Issue preclusion (collateral estoppel) could not be applied against the Office based on a district court holding in an infringement proceeding, because the Office was not a party to the earlier infringement proceeding and did not have ‘a full and fair opportunity’ to litigate the issue.”

This means that while collateral estoppel can apply in some cases, it’s limited and doesn’t prevent the USPTO from reexamining claims previously upheld by a court.