Post-Grant Proceedings Update - October 2026

35 U.S.C. § 325(d) and the Prior Art That Follows You Into Ex Parte Reexamination

35 U.S.C. § 325(d) (“Section 325(d)”) permits the U.S. Patent and Trademark Office (“USPTO” or the “Office”) to decline review when “the same or substantially the same prior art or arguments previously were presented to the Office.” By its terms, the provision reaches not only inter partes review (“IPR”) petitions before the Patent Trial and Appeal Board (“PTAB” or the “Board”) but also requests for ex parte reexamination (“reexamination”) at the USPTO. As reexamination filings have climbed, a recurring question has followed: what happens when a reexamination request presents prior art or arguments the Office has already seen, especially in a previously-filed petition for inter partes review?

A line of authority—anchored by the Federal Circuit’s decision in In re Vivint—confirms that prior art presented in an earlier proceeding can support denial of a later reexamination request that relies on it. But recent decisions applying that authority have pointed in different directions, leaving it unclear how far the Office will carry Section 325(d) in the reexamination setting.

The Statutory Framework

Section 325(d) exists to prevent parties from forcing the Office and patent owners to relitigate patentability questions the Office has already confronted. In the IPR context, the Board applies it through the two-step framework of Advanced Bionics, LLC v. Med-El Elektromedizinische Geräte GmbH, IPR2019-01469, Paper 6 (PTAB Feb. 13, 2020): whether the same or substantially the same art or arguments were previously presented to the Office and, if so, whether the petitioner has shown that the Office erred in a manner material to patentability. That framework distills the factors of Becton, Dickinson & Co. v. B. Braun Melsungen AG, IPR2017-01586, Paper 8 (PTAB Dec. 15, 2017), and the Office’s May 2025 precedential decision in ECTO World, LLC v. RAI Strategic Holdings, Inc., IPR2024-01280, Paper 16 (PTAB June 25, 2025), which refined the “material error” inquiry at the second step.

In re Vivint: Section 325(d) Reaches Reexamination

The foundational decision is In re Vivint, Inc., 14 F.4th 1342 (Fed. Cir. 2021). A challenger had filed a succession of IPR petitions against the same patent, the last of which the Board declined to institute on discretionary grounds, citing incremental, repetitive filing. More than a year later, the challenger sought reexamination of that patent, carrying over arguments from the failed petition—including two of the four patentability questions reproduced nearly word-for-word—and the Office ordered reexamination.

The Federal Circuit vacated. It held that Section 325(d) “applies to both IPR petitions and requests for ex parte reexamination,” and that the Office may reconsider an order granting reexamination on that basis. Id. at 1354. On the facts, it was arbitrary and capricious for the Office to deny the IPR and then grant a “nearly identical reexamination request that is even more abusive.” Id. The court also explained that a request may raise a “substantial new question of patentability”—the threshold showing required to order reexamination under 35 U.S.C. § 303(a)—yet still be subject to discretionary denial under Section 325(d): meeting the threshold to order reexamination does not clear Section 325(d). Id. at 1350.

For several years, Vivint’s practical effect was modest. The Office frequently distinguished it, ordering reexamination where a request added a new reference or argument, or lacked the pattern of serial filing present in Vivint itself. Only a small number of Section 325(d) denials in reexamination proceedings had issued through early 2026. Decisions from 2026, however, show the Office reaching opposite results on comparable facts.

Divergent 2026 Decisions

On May 22, 2026, the Office denied a request for reexamination (Reexamination No. 90/015,984) under Section 325(d). The stated basis was that the request relied on prior art and arguments overlapping with those raised in an earlier IPR petition against the same patent, which the Office had already declined to institute on discretionary grounds. See Geotab Inc. v. Fractus, S.A., IPR2025-00929, Paper 12 (PTAB Sept. 12, 2025). The Office identified the overlapping grounds it treated as material, observing that the reexamination request targeted the same claims with the same prior art or combinations.

The significant feature is what the earlier IPR denial did—and did not—involve. Because the IPR had been denied on discretionary grounds, the Office never evaluated the merits of the asserted art. Yet the discretionarily denied petition was still treated as art “previously presented” sufficient to support denial of the follow-on reexamination. The decision thus indicates that an IPR petition resolved at the discretionary denial stage—without any merits determination—may nonetheless supply the Section 325(d) basis to deny a later reexamination raising the same art.

Other 2026 orders point the other way, and on facts closer to Geotab—reexamination ordered even though the overlapping IPR had itself been discretionarily denied. In Reexamination No. 90/016,221 (Order Granting Reexamination, July 28, 2026), the requester sought reexamination of a patent it had earlier challenged in an IPR that the Board discretionarily denied (Monolithic Power Systems, Inc. v. Reed Semiconductor Corp., IPR2025-00165, Paper 13 (PTAB Apr. 14, 2026)). Several of the asserted references had appeared in that petition, but the examiner ordered reexamination. Because the discretionary denial “provided no discussion of the merits” of the overlapping art, the examiner reasoned that consideration of that art in reexamination would come “in a new light,” as “the first consideration on the merits”—and separately relied on additional references that had not been before the Office at all (Order Granting Request for Ex Parte Reexamination, Ex Parte Reexamination of U.S. Patent No. 7,960,955, Control No. 90/016,221, at 7-8 (U.S.P.T.O. July 28, 2026)). On those facts, the examiner concluded that denial under Section 325(d) was “not appropriate under the specific facts of this case.”

Read together, these decisions frame the current uncertainty. Both involved reexamination requests overlapping with a discretionarily denied IPR, yet Geotab treated that overlapping art as “previously presented” and denied reexamination, while the order in Reexamination No. 90/016,221 treated the absence of any merits evaluation in the underlying denial as a reason the art had not truly been considered—and ordered reexamination. Whether Geotab signals a broader tightening of Section 325(d) in reexamination or proves to be a fact-specific outlier is, at this stage, unclear.

Observations

Ex parte reexamination retains distinctive features—a substantial-new-question threshold, no Fintiv-style parallel-litigation inquiry, no one-year filing bar, the possibility of anonymous filing, and no statutory estoppel. The recent decisions do not disturb any of those features. What they clarify is the reach of a distinct limit: the Office’s authority to decline reexamination when the same or substantially the same prior art or arguments were previously presented to it, including in a prior IPR—and, per Geotab, even where that proceeding was resolved on discretionary grounds without a merits evaluation. For a patent owner confronting a reexamination request that overlaps with a prior proceeding, a timely Section 325(d) petition mapping that overlap is the mechanism through which these principles are raised. How consistently the Office will apply that limit, however, remains an open question: as the 2026 orders discussed above illustrate, overlap with a discretionarily denied IPR has produced opposite outcomes within the same year. Section 325(d) is likely to remain a focal point as the Office recalibrates its post-grant practice, and the emerging reexamination decisions will determine whether Geotab reflects a durable trend or an early one-off.

//////////
Ross Misskelley, Associate
rossmisskelley@quinnemanuel.com