Practitioners before the Patent Trial and Appeal Board are well-acquainted with the statutory bar on judicial review of institution decisions. But what happens when the Board defers—for more than a year—a decision to rehear its non-institution decision, waiting for the Federal Circuit to clarify claim construction in parallel litigation involving the same patent and same parties? In Ethanol Boosting Systems, LLC v. Ford Motor Company, Appeal 2024-1381 (Fed. Cir. Dec. 23, 2025) (“EBS”), the Federal Circuit addressed this scenario, providing a practical reminder of the limits of appellate review and the Board’s procedural discretion.
The relevant dispute began when the Ford Motor Company filed IPR petitions challenging several patents owned by the Massachusetts Institute of Technology and licensed to Ethanol Boosting Systems (EBS). While those petitions were pending, a district court issued a claim construction order in parallel litigation involving the same parties and patents. After the Board initially denied those petitions, Ford requested rehearing, urging the Board to wait for the Federal Circuit’s decision in the appeal of the court’s claim construction before deciding its request. The Board obliged, effectively staying its rehearing decision for over a year until the Federal Circuit clarified the disputed claim terms. See Slip Op. at 6–7; Ethanol Boosting Sys., LLC v. Ford Motor Co., Appeal 2021-1949 (Fed. Cir. July 18, 2022) (non-precedential). Only then did the Board grant rehearing, instituting the IPRs and eventually canceling the challenged claims as unpatentable, and setting the stage for EBS’s appeal.
On appeal, EBS argued that the Board’s delay in deciding Ford’s rehearing requests was an ultra vires agency action, not authorized by statute, and that the subsequent institutions of IPR were therefore improper. EBS asked the Federal Circuit to vacate the Board’s judgment, contending that the stay tainted the proceedings. EBS, Slip Op. at 8–9. The Federal Circuit declined, based on the statutory bar on judicial review of IPR institution decisions: “The determination by the Director whether to institute an inter partes review under this section shall be final and nonappealable.” Id. at 10 (quoting 35 U.S.C. § 314(d)). The court explained that challenges to the timing or propriety of institution decisions are not subject to judicial review—even if styled as objections to a stay. Id. at 11–12 (citing Thryv, Inc. v. Click-To-Call Techs., LP, 590 U.S. 45 (2020) (discussed here)). The court emphasized that parties cannot circumvent the statutory bar by relabeling their appellate challenge if the practical effect is to contest the Board’s institution.
EBS tried to invoke the Supreme Court’s “shenanigans” exception, arguing that the Board’s delay exceeded its statutory authority. See Cuozzo Speed Techs., LLC v. Lee, 579 U.S. 261, 275 (2016) (stating that appellate review of an institution decision may be appropriate to address “shenanigans”). The Federal Circuit was unpersuaded, noting there is no statutory deadline for deciding rehearing requests, and the Board had “sound reasons” for awaiting the Federal Circuit’s claim construction, which was relevant to the IPRs concerning the same patent claims. EBS, Slip Op. at 13–14. The panel distinguished this situation from cases where an agency acts outside its statutory authority in a way that might be reviewable, such as canceling patent claims for indefiniteness. Even so, nearly a decade after the Supreme Court’s decision in Cuozzo Speed, the scope of Patent Office activity constituting shenanigans remains a mystery.
Ultimately, the Federal Circuit concluded that the statute barred review of EBS’s challenge to the timing and manner of the Board’s institution decision. Id. at 12, 14. For practitioners, this decision is a reminder that unless an agency’s action falls within a recognized exception, challenges to the institution decision—including tacit maneuvers like deferring a rehearing decision for more than a year—remain unreviewable. The Board’s discretion in managing its docket, especially in the face of parallel litigation, is broad and here again insulated from appellate second-guessing. The Patent Office’s new Director has further ensured his institution decisions remain unreviewable because, recently, these decisions have been mere summary notices offering no supporting reasoning, much less reasoning that could be critiqued in a rehearing request. See Director Memo re “Director Institution of AIA Trial Proceedings” (Oct. 17, 2025) (link and slides).
Beyond the statutory reviewability bar, the Federal Circuit also affirmed the Board’s substantive obviousness determinations. The court determined that substantial evidence supported the Board’s findings regarding the disclosure of all challenged claim limitations in the prior art and the motivation to combine the prior art. EBS, Slip Op. at 19–24. The court rejected EBS’s arguments that the Board relied on new theories or failed to adequately explain its rationale. The court concluded that the Board’s decisions were sufficiently reasoned and supported by the record, affirming the unpatentability of all challenged claims. Id. at 25.