Permissibility of Applicant Admitted Prior Art (AAPA) in Inter Partes Reviews (IPRs)

On April 23, 2025, in a precedential decision, the Court of Appeals for the Federal Circuit (CAFC) further clarified that 35 U.S.C. § 311(b) imposes a categorical limit on the types of prior art that can form the basis of an inter partes review (IPR) challenge.  While applicant-admitted prior art (AAPA) may still be cited for background or context in district court litigation or during examination, its role in IPRs is strictly constrained.

Qualcomm I

In a dispute centering on the use of AAPA IPR proceedings, Apple Inc. filed two IPR petitions (IPR2018-01315 and IPR2018-01316) with the Patent Trial and Appeal Board (Board) challenging different sets of claims of Qualcomm’s U.S. Patent No. 8,063,674 (“the ‘674 Patent”). Each petition alleged that the challenged claims were unpatentable in view of a combination of prior art references and AAPA disclosed in the specification of the ‘674 Patent itself – namely, statements made by Qualcomm during prosecution that characterized the state of the prior art. Apple argued that this AAPA, when combined with other patents and printed publications, rendered the claims unpatentable under 35 U.S.C. § 103. Qualcomm conceded that the combination of the AAPA and the prior art references together taught the challenged claims but contested the use of AAPA as the basis for the rejection in an IPR proceeding.

The Board agreed with Apple and decided that Apple's use of AAPA was proper under the statute because “ 'prior art consisting of patents or printed publications' includes AAPA because it is prior art contained in a patent. See Qualcomm Inc. v. Apple Inc. (Qualcomm I), 24 F.4th 1367, 1372 (Fed. Cir. 2022).

Qualcomm appealed the decision to the United States Court of Appeals for the Federal Circuit. On appeal, Qualcomm argued that the Board had erred as a matter of law in permitting the use of AAPA as “prior art consisting of patents or printed publications” under § 311(b), alleging that “the 'patents or printed publications' that form the 'basis' of a ground for inter partes review must themselves be prior art to the challenged patent.” See id. at 1374. The Federal Circuit agreed with Qualcomm holding that AAPA “may not form the 'basis' of a ground in an inter partes review, and it is therefore impermissible for a petition to challenge a patent relying on solely AAPA without also relying on a prior art patent or printed publication”. See id. at 1377. The Federal Circuit added that “any descriptions of the prior art contained in the challenged patent” are excluded from that conclusion. See id. The Federal Circuit also clarified that AAPA is not categorically excluded from an inter partes review, holding that AAPA may be used “when assessing whether that patent’s claims would have been obvious”, and to determine “what a skilled artisan would have known at the time of the invention”. See id. at 1375–1376.

USPTO Updated Guidance

In June 2022, subsequent to the conclusion of Qualcomm I, the U.S. Patent and Trademark Office (PTO) issued a guidance memorandum on § 311(b) (“Updated Guidance on the Treatment of Statements of the Applicant in the Challenged Patent in Inter Partes Reviews Under § 311(b),” June 9, 2022 (“Updated Guidance”)) that updated and replaced a previously provided memorandum on the same matter. The Updated Guidance interprets § 311(b) to require an “in combination” rule in which if “an IPR petition relies on admissions in combination with reliance on one or more prior art patents or printed publications, those admissions do not form 'the basis' of the ground and must be considered by the Board in its patentability analysis.” See Updated Guidance, p. 4. In addition, the patentee’s admissions may also be used to supply missing claim limitations that were generally known prior to the invention, support a motivation to combine particular disclosures, or demonstrate the knowledge of the ordinarily-skilled artisan at the time of the invention for any other purpose related to patentability. See id.

Furthermore, the Updated Guidance provides examples of statements that may be included with admissions made in the specification, such as, but not limited to, “It is well known that . . . . ,” “It is well understood that . . . . ,” or “One of skill in the art would readily understand that. . . . ,” or phrases that may be used to describe technology such as, but not limited to, “prior art”, “conventional”, “well-known”, or the like. See id. at p. 4.

Qualcomm II

On remand, the Board again found certain claims of Qualcomm’s ‘674 Patent unpatentable. This time, the Board relied on the Updated Guidance from the PTO, issued in response to the Qualcomm I decision. The new guidance attempted to thread a statutory needle, asserting that AAPA could be used not as a “basis” for an IPR ground, but as a “secondary reference” or “contextual evidence” in combination with prior art patents or printed publications.

Apple argued that it was not relying on AAPA as a standalone ground, but rather as part of the evidentiary landscape for evaluating obviousness. The Board adopted that interpretation and issued a second final written decision finding the challenged claims obvious.

Qualcomm appealed again (Qualcomm Inc. v. Apple Inc. (Qualcomm II), 134 F.4th 1355 (2025)), asserting that the Board had effectively circumvented the Federal Circuit’s earlier ruling by recharacterizing AAPA as a “supporting” or “contextual” reference, despite the fact that the AAPA continued to play a central role in the obviousness rationale. Qualcomm argued that this interpretation violated both the letter and the spirit of § 311(b), which explicitly restricts IPR grounds to printed publications and patents—not internal admissions in the challenged patent itself. In particular, Qualcomm raised three issues on appeal, namely, whether the Board’s decision to consider Ground 2 during IPR proceedings, based on its interpretation and application of § 311(b), is reviewable by this court, whether the Board misinterpreted § 311(b), and whether the Board erred in determining that Ground 2 complied with § 311(b).

In a decision issued on April 23, 2025, the Federal Circuit again sided with Qualcomm. The court reaffirmed its earlier interpretation of § 311(b), emphasizing that AAPA cannot be used as part of the “prior art basis” for an IPR ground, even if presented alongside qualifying patents or publications. The court rejected the PTO’s revised guidance, holding that its functional effect was to reintroduce AAPA as a substantive ground, contrary to the statutory text.

The court further clarified that § 311(b) imposes a categorical limit on the types of prior art that can form the basis of an IPR challenge. While AAPA may still be cited for background or context in district court litigation or during examination, its role in IPRs is strictly constrained. Because the Board’s finding of unpatentability once again rested on an impermissible use of AAPA, the Federal Circuit vacated the Board’s decision for a second time.

Practical Implications for Patent Applicants

Patent applicants should exercise caution when drafting background sections. Describing existing technologies as "well known," "conventional," or "prior art" may lead to binding admissions that could be used to challenge the validity of the claims. Employing neutral language and avoiding unnecessary concessions may mitigate this risk.

Practical Implications for Patent Challengers

Challengers must recognize that while AAPA is a valuable tool in litigation and during USPTO examination and reexamination, its use in IPR proceedings is constrained. AAPA cannot form the basis of an IPR ground under § 311(b). However, it may still be cited to provide context or support for an obviousness rationale when used in combination with qualifying printed publications or patents, provided it does not constitute the basis of the challenge.