-
USPTO Proposes PTAB Rule Revisions To Curb Serial And Parallel Challenges, Bolster Patent Reliability
10/21/2025The United States Patent and Trademark Office has proposed a significant overhaul of its rules for instituting inter partes reviews (IPRs) at the Patent Trial and Appeal Board (PTAB). Framed as a procedural reform aimed at enhancing fairness, efficiency, and predictability, the rule would narrow the circumstances under which the PTAB would institute IPRs—particularly where claims have already withstood validity scrutiny elsewhere or where parallel litigation is poised to resolve overlapping issues first. If adopted, the rule would likely materially reshape strategic decision-making for patent challengers and owners alike, with especially notable implications for high-volume technology litigants and small and medium-sized enterprises (SMEs) that depend on enforceable IP to attract capital and compete.
The proposed rule reflects the agency’s concern that serial and parallel validity attacks erode the reliability of issued patents and increase litigation costs in ways Congress did not intend when it created IPRs as a “quick and cost-effective alternative” to district court validity litigation. The Office cites the substantial incidence of multiple petitions per patent and the prevalence of co-pending district court cases involving the same issues. Repeated de novo patentability review by the PTAB under the lower (than district court) preponderance of the evidence standard in IPRs, the USPTO explains, can destabilize even “strong” patents over time. The result is diminished investment incentives, particularly acute for startups and SMEs that rely on patent-backed differentiation to challenge incumbents. By more sharply defining when IPRs are appropriate and channeling duplicative issues to a single forum, the proposal seeks to reinforce quiet title, reduce duplicative costs, and promote greater decisional consistency.
The agency also notes a crucial capacity trade-off: every hour PTAB judges devote to IPR is an hour not spent on ex parte appeals of original patent prosecution—often the only path for applicants to secure patent rights or judicial review of rejections. With appeal pendency already above target levels, the Office views refocusing IPRs on the most suitable disputes as essential to maintaining the integrity and throughput of the broader patent system.
At the center of the proposal are three institution gatekeepers—one requiring a forum-choice stipulation, another deferring to prior merits outcomes, and a third avoiding overlap with proceedings likely to conclude first—supplemented by a narrow “extraordinary circumstances” safety valve.
The first gatekeeper is a required stipulation for efficiency. Under the proposed rule, the Office would not institute or maintain an IPR unless each petitioner commits that, if trial is instituted, it and its privies will not pursue invalidity grounds under 35 U.S.C. §§ 102 or 103 regarding the challenged patent in any other proceeding, including in district court and before the ITC. Petitioners must file the stipulation at the PTAB and in any other tribunal where the patent is being litigated. This is intended to ensure IPRs serve as a substitute for a phase of litigation rather than as a duplicative companion, aligning with congressional expectations and prior PTAB precedent requiring narrowing stipulations.
The second gatekeeper is deference to claims previously upheld. Under the proposed rule, institution would be barred where the challenged claim—or the independent claim from which it depends—has already survived prior validity scrutiny under §§ 102 or 103 as reflected in any of the following: a district court verdict or judgment after trial; a district court grant of summary judgment; an initial or final ITC determination; a PTAB final written decision; an ex parte reexamination outcome; or a Federal Circuit decision. The Office’s premise is that such claims have been adequately vetted and further de novo PTAB review is not in the system’s or economy’s best interests. Patent challengers would still retain a full opportunity to press invalidity in court.
The third gatekeeper is avoidance of parallel track duplication. Under the proposed rule, institution would be denied where, more likely than not, a validity determination under §§ 102 or 103 will occur before the IPR’s statutory final decision deadline in: a district court trial, an ITC initial or final determination, or another PTAB final written decision. This time-based filter aims to conserve resources and to reduce the risk of inconsistent outcomes, by allowing the forum poised to reach a decision first to proceed without PTAB overlap.
Last, there would be a narrow extraordinary-circumstances escape hatch. Under the proposed rule, the Director of the Office may personally institute notwithstanding the foregoing limitations if extraordinary circumstances warrant it—such as when a prior challenge was brought in bad faith to block future review, or where a substantial change in statute or Supreme Court precedent renders earlier outcomes obsolete. Routine developments—new prior art, new experts, standard changes in caselaw short of Supreme Court shifts, new legal arguments, or a prior challenger’s failure to appeal—do not qualify. Frivolous use of this pathway may draw sanctions, including fee awards.
For patent owners, particularly SMEs and startups, the proposed rule would strengthen the reliability of adjudicated claims and reduce the burden of defending duplicative, rebranded, or sequential challenges. It would make it harder for repeat filers to keep a cloud over patents that have already survived meaningful scrutiny, and it should, in practice, simplify licensing negotiations and litigation by narrowing the number of active fora and theories.
For petitioners, especially frequent filers in complex, high-stakes sectors, the stipulation and preclusion provisions will demand earlier and more decisive forum selection, tighter coordination with district court strategies, and more careful sequencing. The risk calculus changes: electing IPR will require forgoing parallel § 102/103 invalidity in court, and the availability of IPR will be curtailed if the claim has previously been upheld or if a parallel proceeding is likely to get there first. The Office acknowledges a small increase in filing preparation time—approximately one added hour per petition to prepare and file the required stipulation—but anticipates overall cost reductions as duplicative efforts diminish.
For the system at large, the Office expects the proposed rule modifications to provide greater predictability in institution decisions, greater clarity for parties assessing whether to petition, and fewer inconsistent merits outcomes across tribunals. By reducing IPR load in cases ill-suited for PTAB review, the Office asserts that its proposal should also free adjudicatory capacity for ex-parte appeals, with downstream benefits for patent quality and time-to-rights in the innovation pipeline.
The proposal is framed as a procedural rule governing institution and the relationship of IPR to other proceedings, anchored in the Director’s statutory discretion and rulemaking authority. The agency sets out its analyses under the Administrative Procedure Act and relevant executive orders, concluding that the rule is not economically significant, imposes minimal incremental paperwork burden, and is likely to reduce aggregate litigation costs without materially burdening small entities. The USPTO invites public comment within the stated period and has notified OMB regarding the modest revision to the relevant information collection.
The USPTO’s proposed PTAB rule targets the most persistent sources of duplicative cost and uncertainty in AIA practice: serial and parallel challenges and overlapping validity contests across fora. By requiring a forum-commitment stipulation, deferring to prior merits validations, and prioritizing proceedings likely to finish first, the Office asserts that the proposed rule would recalibrate IPR toward its intended role as a focused alternative—not an additional layer—of validity review. If finalized as proposed, it will materially affect litigation strategy, increase the finality and value of adjudicated patent claims, and reallocate PTAB capacity to matters where the PTAB’s involvement delivers the most systemic benefit.
