IP Hot Topic: “Multiple” AIA Petitions: Clarifying the Terminology

The patent bar has been involved in discussions of how to address “multiple” AIA petitions challenging a same patent in view of changes at the Patent Trial and Appeal Board (PTAB) since March 2025, as well as a pending Notice of Proposed Rulemaking (NPRM) from October 2025. What is not clear, however, is whether everyone has a singular understanding of what “multiple” petitions actually means.

Generally speaking, the term “multiple petitions” refers to a second or additional petition filed by any petitioner challenging a same patent (not necessarily the same claims) as a first petition. A first AIA petition is not itself a multiple petition. And any subsequent petition is not necessarily filed by the first petitioner or someone related to them.

The USPTO has provided data over the years as it relates to the filing and institution of multiple petitions. See, e.g., October 2025 Multiple Petitions Study “Addendum” and July 2023 Multiple Petition Study Update.

Such studies basically say the same thing: before 2025, ~70% of AIA petitions were first petitions, and a bit less than 20% were second petitions. Thus, ~90% of all AIA petitions were first or second petitions. It was rare for a patent to be challenged three or more times, and of those, a significant majority involved unrelated petitioners who were separately sued by the patent owner and/or occurred before 2017.

The PTAB itself rarely instituted multiple petitions after the USPTO implemented jurisprudence addressing the issue, solidly in place since 2020. See e.g., General Plastic (precedential Oct. 18, 2017); Valve I (precedential May 7, 2019); Valve II (precedential Aug. 2, 2019); PTAB’s Consolidated Trial Practice Guide (Nov. 2019), pp. 59-61.

As noted in an Executive Summary of the 2023 Multiple Petition Update, after the USPTO issued guidance from 2017-2020, there was a noticeably reduced occurrence of petitioners filing multiple petitions. And PTAB instituted fewer AIA trials based on more than one petition, and even then, only under certain rare circumstances.

Lastly, it is important to note that phrasing of “one of multiple petitions” in the October 2025 Multiple Petition study (and October 2025 NPRM) includes in its count any first petition if any party—even if entirely unrelated to the first petitioner—files a second petition. See October NPRM (stating “[a]pproximately 54% of all IPR petitions filed since the passage of the AIA are one of multiple petitions against the same patent.”).

Thus, the statistics show there are few occurrences where a same petitioner or unrelated petitioner files multiple petitions against a single patent.