Trending at the PTAB: IPR Memo and Its Fed. Circ. Backdrop

1. Revised Petition Standards: The USPTO's new memorandum, effective September 1, mandates that IPR petitions must strictly comply with Rule 104(b)(4) and identify where each challenged claim element is found in prior art patents or printed publications, and petitioners may no longer rely on applicant-admitted prior art, expert testimony, common sense, and other non-prior art evidence to do so.
   
   
2. Conflict with Federal Circuit Precedent: The new USPTO rules aim to align with Federal Circuit precedent but acknowledges that the rules directly conflict with the recent Shockwave decision, which permits "general knowledge" to supply missing claim limitations.
   
   
3. Practical Implications: Starting September 1, petitioners should carefully map challenged claims directly to prior art disclosures without relying on general background knowledge, while patent owners should scrutinize petitions for compliance with the new guidelines.

There are new rules for when and how evidence other than patents or printed publications can be considered in inter partes reviews. On July 31, acting Director Coke Morgan Stewart of the U.S. Patent and Trademark Office issued a memorandum that makes significant changes to inter partes review practice before the Patent Trial and Appeal Board.[1]

The memorandum, set to take effect on Sept. 1, mandates strict compliance with Title 37 of the Code of Federal Regulations, Section 42.104(b)(4), which requires IPR petitions to "specify where each element of the claim is found in the prior art patents or printed publications relied upon."[2]

Importantly, the memorandum highlights that the following categories may not be used to supply a missing claim limitation to satisfy Rule 104(b)(4): (1) applicant admitted prior art; (2) expert testimony; (3) common sense; and (4) other evidence that is not prior art consisting of patents or printed publications. These are collectively considered "general knowledge."[3]

While the memorandum was issued with the goal of reflecting current precedent from the U.S. Court of Appeals for the Federal Circuit, the USPTO acknowledged that it conflicts with the Federal Circuit's recent Shockwave decision, which expressly permits general knowledge to supply a missing claim limitation.[4]

Despite this tension, the USPTO emphasized that strict adherence to Rule 104(b)(4) aligns with the agency's broader objectives of providing greater "certainty to the parties, the Board, and the public."[5]

Prior PTAB Guidance

Prior to the July 31 memorandum, the PTAB applied a flexible approach to IPR institutions. Memoranda issued in 2020 and 2022 by previous directors of the USPTO afforded the PTAB discretion in complying with Title 35 of the U.S. Code, Section 311(b), which states that IPRs may only be instituted "on the basis of prior art consisting of patents or printed publications."[6]

These memoranda clarified that while general knowledge could not be the sole basis of an IPR petition to satisfy Section 311(b), in practice, practitioners were still permitted to rely on general knowledge, in combination with one or more prior art patents or printed publications, for the following: (1) to supply missing claim limitations that were generally known in the prior art; (2) to support a motivation to combine prior art references; and/or (3) to demonstrate knowledge of a skilled artisan.[7]

The 2022 memorandum specifically emphasized that the PTAB should not deny a petition where the petitioner used general knowledge to satisfy a missing claim limitation under Rule 104(b)(4).[8]

Revised Petition Standards

With the July 31 memorandum, petitioners may no longer rely on general knowledge to satisfy Rule 104(b)(4), but that does not mean general knowledge has no place in IPR petitions. General knowledge may still be used, albeit in a much narrower scope, to support a motivation to combine or to demonstrate the knowledge of a skilled artisan.[9]

The July 31 memorandum reflects a renewed emphasis on the statutory boundaries of Section 311(b), while aiming to bring the PTAB in line with current Federal Circuit precedent, to avoid the "risk of further litigation on this point."[10]

Federal Circuit Precedent

The July 31 memorandum specifically called out three Federal Circuit precedential cases.

Qualcomm I

In its 2022 decision in Qualcomm Inc. v. Apple Inc., the Federal Circuit held that applicant admitted prior art is not "prior art consisting of patents or printed publications" under Section 311(b), therefore it cannot form "the basis" of an IPR petition.[11]

The Federal Circuit examined a similar statute, Section 301(a), which is relevant to ex parte reexamination of patents. This statute states that "[a]ny person at any time may cite to the Office in writing — (1) prior art consisting of patents or printed publications which that person believes to have a bearing on the patentability of any claim of a particular patent."[12] Prior judicial interpretations of Section 301(a) excluded "patents which themselves are not prior art."[13]

The Federal Circuit held that, to remain consistent with interpretations of Section 301(a), Section 311(b) must also bar the use of applicant admitted prior art as the basis of the grounds in an IPR because "it is not contained in a document that is a prior art patent or prior art printed publication."[14] The Federal Circuit remanded to the PTAB to determine whether the applicant admitted prior art impermissibly formed the basis for the petitioner's IPR challenge.

Qualcomm II

In its Qualcomm v. Apple decision this year, the Federal Circuit rejected the USPTO's "in combination" rule and held that Section 311(b) should be interpreted to exclude the use of applicant admitted prior art, whether as the basis, or part of the basis, of a ground to institute an IPR.[15] The Federal Circuit did not bar the use of applicant admitted prior art in its entirety, and reaffirmed that applicant admitted prior art can be used for certain uses, as described in Qualcomm I, as long as the applicant admitted prior art is not the basis of an IPR in contravention with Section 311(b).[16]

Shockwave

On July 14, two weeks before the director issued the July 31 memorandum, the Federal Circuit held in Shockwave Medical Inc. v. Cardiovascular Systems Inc. that while Qualcomm I and Qualcomm II require that only patents and printed publications may form the basis of an IPR petition, applicant admitted prior art "can be important evidence of general background knowledge, and general knowledge can be used to supply a missing claim limitation."[17]

While the USPTO states that its July 31 memorandum was issued to reflect current Federal Circuit precedent like Qualcomm I and II, it also seems to acknowledge the direct conflict with the Federal Circuit's recent Shockwave decision. While the memorandum bars the use of general knowledge to supply a missing claim limitation to satisfy Rule 104(b)(4), the Federal Circuit held that general knowledge could be used to supply a missing claim limitation under Section 311(b).

The USPTO accepts this discrepancy in the memorandum in an effort to provide certainty to the parties and improve the efficiency of the USPTO, stating, "[w]hile Rule 104(b)(4), as applied in some cases, may be narrower than 35 U.S.C. § 311(b), enforcing Rule 104(b)(4) is the best course of action to provide certainty to the parties, the Board, and the public, and to allow for the efficient administration of the Office."[18]

Practical Implications for Petitioners and Patent Owners

While the July 31 memorandum was directed to IPRs, petitioners and patent owners should not be surprised if this memorandum affects post-grant review proceedings. Under Title 37 of the Code of Federal Regulations, 42.204(b)(4), a petition "must specify where each element of the claim is found in the prior art."[19] Because this language closely mirrors the requirements under Rule 104(b)(4), practitioners should be on the lookout either for a similar memorandum applying to PGRs or if this memorandum will be applied to PGR proceedings beginning Sept. 1, even if the July 31 memorandum does not directly address these proceedings.

Starting Sept. 1, petitioners should take care to map out elements of a challenged claim to disclosures in the prior art precisely (i.e., patents and printed publications). Petitioners should carefully review these petitions to ensure that general background knowledge was not used to supply a missing claim limitation to fill in missing gaps from the prior art.

Conversely, patent owners should carefully scrutinize petitions to ensure they comply with this new guidance from the USPTO. If general knowledge is used beyond providing a motivation to combine or demonstrating the knowledge of a skilled artisan, then the patent owner should flag the petition as not complying with Rule 104(b)(4).

As the Sept. 1 deadline approaches, practitioners must navigate a shifting landscape, making precision in drafting or scrutinizing an IPR petition not just strategic, but essential.

Endnotes

[1] Memorandum from Director Coke Morgan Stewart, Enforcement And Non-Waiver of 37 C.F.R. § 42.104(B)(4) and Permissible Uses of General Knowledge in Inter Partes Reviews at 2 (July 31, 2025) ("2025 Memorandum").

[2] 37 C.F.R. § 42.104(b)(4).

[3] 2025 Memorandum at 2.

[4] Shockwave Med., Inc. v. Cardiovascular Sys., Inc., 142 F.4th 1371, 1378–379 (Fed. Cir. 2025).

[5] 2025 Memorandum at 2–3.

[6] See generally Memorandum from Director Andrei Iancu, Treatment Of Statements of the Applicant in the Challenged Patent In Inter Partes Reviews Under § 311 (August 18, 2020) ("2020 Memorandum"); Memorandum from Katherine K. Vidal, Updated Guidance on the Treatment of Statements of the Applicant in the Challenged Patent In Inter Partes Reviews Under § 311 (June 9, 2022) ("2022 Memorandum").

[7] 2022 Memorandum at 4.

[8] Id. at 6.

[9] 2025 Memorandum at 1–2.

[10] Id. at 2–3.

[11] Qualcomm Inc. v. Apple Inc., 24 F.4th 1367, 1373–375 (Fed. Cir. 2022).

[12] 35 U.S.C. § 301(a).

[13] Id. at 1374.

[14] Id. at 1375.

[15] Qualcomm Inc. v. Apple Inc., 134 F.4th 1355, 1364–366 (Fed. Cir. 2025).

[16] Id. at 1365.

[17] Shockwave Med., Inc., 142 F.4th at 1378–379.

[18] 2025 Memorandum at 2–3.

[19] 37 C.F.R § 42.204(b)(4).