Five USPTO/PTAB Developments That Could Affect Your Patent Strategy

October 2026 Edition

A sound patent planning strategy depends on more than knowing the rules. It also requires recognizing when familiar practices need another look. For patent practitioners and in-house IP counsel, changes in USPTO procedures and PTAB guidance can alter how best to protect an invention, respond to a rejection or pursue an appeal. Recent developments offer several reasons to reassess those approaches—and, in some cases, new opportunities to advance an application. The practical question is where to adjust. Below, we examine five updates affecting filings, delay petitions and prosecution strategy, with a focus on what each means for your next decision.

Check Complex Formatting Before Filing

Patent Center is the online filing and management system of the USPTO that allows users to electronically submit and manage patent applications as well as related documents. During pre-submission processing, Patent Center will now convert DOCX submissions directly to TIFF rather than first converting them to PDF. Applicants may review the TIFF before filing and obtain PDF, DOCX, and XML versions afterward. Because the USPTO continues to treat the DOCX file as the source and evidentiary copy, applicants should carefully review the original document. Practitioners should give particular attention to content such as claims, tables, equations, chemical structures, whose formatting may not convert as expected.

Delays Over One Year Now Require More Explanation

The USPTO has lowered the information-threshold period for unintentional delay petitions from more than two years to more than one year. For petitions filed on or after August 13, 2026, the USPTO will require additional information establishing that the entire delay was unintentional when the petition is filed more than one year after the date in question (e.g., the date of abandonment or the date when a priority claim was due). This change affects several petition types, including petitions to revive abandoned applications, to accept delayed maintenance fee payments, to accept delayed domestic benefit and foreign priority claims, and to excuse certain failures to act in international design applications. Practitioners addressing an existing delay should review the current requirements rather than rely on the former two-year threshold. Petitions filed after the one-year mark also carry a higher fee. The USPTO’s stated goals for the change are to make patent rights more certain and predictable and to encourage petitioners to file grantable petitions on time. Hence, practitioners should file revival and delayed-claim petitions within one year of the missed date. When a petition falls outside that time frame, they should document the full timeline of the delay from the beginning, and check the information in MPEP 711.03(c) as to what counts as an adequate explanation.

Earlier Expiration May Not Resolve an OTDP Rejection

The Appeals Review Panel (ARP) is a USPTO mechanism through which the Director may initiate review of certain Patent Trial and Appeal Board (PTAB) decisions in ex parte appeals, reexamination appeals, and reissue appeals. In Ex parte Baurin, Appeal No. 2024-002920, the APR addressed obviousness-type double-patenting (OTDP) rejections. The ARP reversed a PTAB decision and reinstated six OTDP rejections involving Sanofi antibody claims. The ARP held that preventing potential harassment through separate ownership of patentably indistinct claims may independently support an OTDP rejection, even when the challenged claims would not have extended the patent term. While the decision was designated precedential, there are some caveats. The ARP itself questioned whether a standalone anti-harassment rationale is sound policy, and suggested that the Federal Circuit should examine this issue. Baurin binds USPTO personnel but not the Federal Circuit or district courts. The ARP also proposed a future framework for OTDP practice at the USPTO, however, that framework is not yet in effect. Because Baurin is binding on examiners, arguing that the challenged claims expire earlier will no longer overcome an OTDP rejection by itself. Responses by practitioners should instead focus on patentable distinctness, or should accept a terminal disclaimer where common ownership of the patents is expected to continue. Given that the ARP itself questioned the anti-harassment rationale and invited Federal Circuit review, practitioners should preserve their objections on the record in cases worth appealing.

A Judge’s Perspective Before the Appeal

Beginning in September, Administrative Patent Judges (APJs) may participate in pre-appeal brief conferences and appeal conferences. An APJ may serve as the third member of a pre-appeal panel or replace the third conferee in an appeal conference. Here, the APJ’s role is advisory. An APJ who participates in a conference may not later serve on the PTAB panel deciding the same appeal. For practitioners, this change may provide an opportunity to obtain an experienced PTAB perspective before proceeding with an appeal, e.g., function as an early test of the case on appeal. That means presenting the strongest arguments concisely, rather than holding them back for the appeal brief. Practitioners should remember that the APJ’s role is advisory and is not appellate review, and that while a favorable or unfavorable conference outcome should inform the decision on whether to proceed, it does not predict how the deciding panel will rule.

Supporting Your Response to a Markush Rejection

In Ex parte Chowdhury, Appeal No. 2025-002261, the Patent Trial and Appeal Board (PTAB) provided guidance on claims containing Markush groupings. The Board held that a Markush grouping is proper when its members form a subgenus and the specification describes those members as performing similar functions in the context of the invention. Although the decision is informative rather than precedential, it may assist practitioners responding to Markush-grouping rejections, particularly in chemical, pharmaceutical, and biotechnology applications. In prosecution, a response to an improper-grouping rejection should follow the framework of identifying the subgenus, then pointing to the specific passages, examples, or data showing that each member serves the common function. In drafting the application, the specification should expressly state that every listed member in each Markush group performs the same function in the claimed invention, and support that statement with examples or data.

Practical Takeaways

Practitioners should review the current petition requirements whenever an unintentional delay has occurred. They should also carefully check DOCX filings and any converted versions, particularly when those documents contain complex or irregular formatting. Finally, recent PTAB and Appeals Review Panel decisions should be considered when developing prosecution and appeal strategies.

________________________