The U.S. Patent and Trademark Office published a notice of proposed rulemaking on October 16, 2025, titled “Revision to Rules of Practice Before the Patent Trial and Appeal Board” announcing its intention to modify the rules that the Patent Trial and Appeal Board (PTAB) will use in determining whether to institute a requested inter partes review (or IPR) of an issued patent. 

Key Elements of the Proposed Rulemaking

The proposed rules would amend Section 42.108 of 37 CFR Part 42, which addresses the threshold decision of whether or not to conduct a requested review. The proposed amendments would create three new categories of bars to IPR institution: 

1. Required Stipulation for Efficiency - Proposed Section 42.108(d) titled “Required stipulation for efficiency” would require an IPR petitioner to stipulate to waiving any prior art based invalidity challenge to the patent under Sections 102 and 103 of the Patent Act in parallel district court or the U.S. International Trade Commission proceedings. This includes waiver of invalidity arguments in the parallel proceeding that could not be brought in an IPR proceeding.

2. Claims Found Valid in Prior Proceedings - Section 42.108(e) titled “Claims found valid in prior proceedings” outlines multiple circumstances in which an IPR would not be instituted because the claims at issue were previously found not invalid or not unpatentable in another proceeding, whether by a district court, the U.S. International Trade Commission, the USPTO, or Federal Circuit review. This section would not bar accused infringers from continuing to challenge validity in district court litigation, but would bar repeated challenges before the USPTO.

3. Parallel Litigation - Section 42.108(f) titled “Parallel litigation” would require the PTAB to deny institution of inter partes review where a parallel proceeding will “more likely than not” reach a decision regarding the validity of a patent before the PTAB’s final written decision. 

The notice also includes a proposed provision that would permit the PTAB to institute review in “extraordinary circumstances,” providing something of a safety valve that would permit the PTAB to refer an exceptional IPR petition to the Director for his personal review.

Support and Opposition from Lawmakers

In response to several requests from industry stakeholders, the USPTO extended the comment period for the notice of proposed rulemaking until December 2, 2025. In total, the notice received over 11,000 comments, of which 1,500 are publicly available for review here. 

Among the most noteworthy, a group of 14 former members of Congress submitted a comment in the form of a letter to the Director of the USPTO John Squires urging him to withdraw and reconsider the proposed new rules. This letter was led by former Senator Patrick Leahy, one of the two named sponsors of the Leahy-Smith America Invents Act (AIA) that created the IPR process back in 2011. In the letter, these lawmakers expressed concern that the notice “runs afoul of the AIA on multiple fronts,” including by expanding the types of validity defenses PTAB petitioners are prevented from raising in district court, binding PTAB petitioners to any prior litigation regarding the patent at issue (including litigation involving third parties), and barring petitioners from requesting an IPR during the full statutory period specified by the AIA. The lawmakers also argued that the proposed rules would embolden patent assertion entities to target vulnerable smaller businesses and would have a severe, negative economic impact. 

By contrast, the other named sponsor of the AIA, former Representative Lamar Smith, submitted his own comment endorsing the policy goals of the proposed new rules. He stated that, from his perspective, the notice “fulfills precisely the intention” that the House Judiciary Committee had professed in its report on the AIA: “using the Director’s procedural authority to address potential abuses and inefficiencies in the PTAB.” His letter asserted that the PTAB should not only be a mechanism for challenging patent validity, but for permitting patent holders to enjoy quiet title.

Similarly, a group of four current lawmakers including Senators Chris Coons and Thom Tillis, who have shown particular interest in intellectual property matters, have also submitted a comment in support of the proposed new rules. In their letter, the lawmakers encouraged the USPTO not only to codify the proposed rules but also to support their bill, the Promoting and Respecting Economically Vital American Innovation Leadership (PREVAIL) Act, which would “make permanent” the proposed rules as law rather than regulations that could be more readily changed in a future administration. According to the lawmakers, the PTAB was intended by Congress to provide an alternative, rather than additional, forum for the resolution of disputes over patent validity. They suggest that both the proposed rules and the PREVAIL Act would eliminate repetitive challenges to patents and promote efficiency allowing inventors to justify investment in future innovation.

Each of the letters submitted by the former and current lawmakers include members of both political parties. With lawmakers reaching across partisan divides to submit comments for and against the proposed new rules—and with even the named sponsors of the AIA finding themselves on opposite sides of the issue—the divisive nature of the notice is clear. It is also clear from the comments that both those in favor and those against recognize that the proposed new rules would fundamentally change the way IPR proceedings are used (or not) in light of parallel patent infringement litigation.