The Supreme Court recently issued an opinion that will increase the certainty for parties to a patent dispute of whether the validity of challenged claims will be decided in a post-grant review process or federal court. SAS Institute v. Iancu involved review of an inter partes review (IPR) proceeding, which is a post-grant review proceeding that is often used as a less costly and quicker alternative to challenging patent claims in federal court. An IPR proceeding is a process under which a third party, such as a competitor or an accused infringer in a concurrent patent litigation case, can ask the director of the Patent and Trademark Office (PTO) to reconsider an issued patent by filing a petition that challenges the validity of some or all of the patent claims. If the director agrees to reconsider the patent, the Patent Trial and Appeal Board (PTAB) then conducts a trial-like proceeding adjudicating the validity of some or all of patent claims and issues a final decision regarding those claims. If the petitioner is not successful in convincing the PTAB that one or more of the challenged claims are invalid, the petitioner is then prevented from later making similar invalidity arguments in federal court for those claims in the final decision.