Clarifying CRU Webinar: Supplemental Examination, Reissues, and Estoppel
Part 2 of 3
Following the February 2026 United States Patent and Trademark Office (USPTO) webinar regarding the Central Reexamination Unit (CRU), patent practitioners received guidance discussing several operational shifts. This blog’s prior assessment focused on the hot topic of Ex Parte Reexamination and covered the production pilots and new anonymous filing requirements.
The freshly released slide deck contains highly specific technical directives concerning supplemental examinations, ex parte reexamination requests, and reissue applications that demand attention. A future blog post will look deeper at the EPR statistics, but there are plenty of interesting takeaways for patent practitioners and IP owners based on the slides posted on the USPTO Hour website.
Supplemental Examination as a Strategic Mechanism
The presentation detailed supplemental examination as a distinct mechanism from standard ex parte proceedings. Patent owners utilize this option to request the Office consider, reconsider, or correct information believed relevant to the patent (p. 9). A primary tactical advantage of this process involves preempting allegations of inequitable conduct during future litigation.
The information evaluated in this proceeding is not restricted strictly to patents or printed publications (p. 9). During the question and answer session, Deputy Commissioner Charles Kim clarified the treatment of subject matter eligibility (35 U.S.C. § 101) and disclosure requirements (35 U.S.C. § 112). Patent owners may introduce these issues “by identifying in the request the discussion of the 101 or 112 issues as an item of information.” The examining corps retains broad discretion; the examiner “can consider those issues as part of a reexamination proceeding that is ordered based on the supplemental examination request,” irrespective of the patent owner’s initial filing choices.
Special Dispatch and Ex Parte Reexamination Constraints
The CRU operates under a statutory mandate of “special dispatch” pursuant to 35 U.S.C. § 305. Deputy Commissioner Kim stated, “The statute requires that the SNQ be determined within three months.” Current CRU performance exceeds this benchmark, averaging “right around two months” for SNQ determinations.
This accelerated pace directly impacts patent owners defending their claims. “Patent owners have to respond within two months instead of the three that’s given for 111(a)’s,” Kim warned. Practitioner flexibility is heavily constrained, limiting patent owners to “a one-month extension of time and they must show cause.”
For third-party requesters, utilizing the streamlined ex parte reexamination option remains popular. The option provides a 50% fee reduction in reexam filing fee for reexamination requests having 40 pages or less which complies with all other requirements of 37 CFR 1.20(c)(1) (p. 14).
Responding to queries regarding volume, Stephen Stein (Management Quality Assurance Specialist, CRU) indicated the Office sees “on average about a 25 percent rate of filing,” highlighting significant utilization of the fee-reduced streamlined option over the past five years.
Stein provided explicit instructions regarding the establishment of an SNQ. A frequent practitioner error involves merely proposing one or more rejections of a patent claim. The request must explicitly identify “new, non-cumulative technical teachings in the prior art references” (p. 15).
Citing MPEP 2216, the CRU requires requesters to pinpoint exactly what is “new.” Combining known references in a novel formulation without explaining the non-cumulative nature of the teachings falls short of the statutory standard.
Regarding administrative compliance, Stein addressed frequent service defects under 37 C.F.R. § 1.248. For third-party requests, “service by transmission is limited to first class mail,” Stein confirmed. Serving opposing counsel via email or facsimile violates the rule absent an explicit prior agreement.
Reissue Practice: Oath, Consent, ADS, and the Bauman Trap
Reissue practice involves rigid procedural rules starting with the oath or declaration. A reissue oath must contain a statement that the applicant believes the original patent to be wholly or partly inoperative or invalid by reason of a defective specification or drawing, or by reason of the patentee claiming more or less than they had the right to claim (p. 16).
If the error statement asserts that the patentee claimed less than they had a right to claim—constituting a broadening error statement—the oath must identify a specific claim the application seeks to broaden. The applicant must point to at least a single word, phrase, or expression in the specification or original claim and explain how it renders the original patent wholly or partially inoperative or invalid (p. 16).
Regarding the consent of the assignee, the individual signing must possess actual or apparent authority (p. 18). An officer of a company, such as a chief executive officer or vice-president, is presumed to possess apparent authority. Actual authority necessitates a clear statement within the submission establishing that the signor is empowered to act on behalf of the assignee. A patent practitioner of record may sign the consent on the assignee’s behalf. If the patent lacks an assignee, the applicant should submit a statement of non-assignment (p. 18).
For continuation or divisional reissue applications, the Application Data Sheet (ADS) requires exact formatting. The ADS must indicate the application is a continuation of the prior pending reissue application and a reissue of the original patent simultaneously (p. 19).
The CRU provided warnings against inadvertently filing a “Bauman type” continuation or divisional application. A Bauman application is a nonprovisional application filed under 35 U.S.C. § 111 that claims benefit to a reissue application under 35 U.S.C. § 120 (p. 21). To prevent this administrative error, applicants filing in Patent Center must select “Reissue application under 35 U.S.C. 251” prior to uploading papers. Selecting the standard utility non-provisional option causes an immediate defect.
If a mistake occurs, converting the filing requires a petition demonstrating the application has indicia of a continuing reissue, such as a reissue oath and double-column formatting (p. 21).
Patent Owner Estoppel in Reissues
The presentation advised patent owners to evaluate 37 CFR § 42.73(d)(3) prior to initiating a reissue. Patent owners must verify the action is not precluded by patent owner estoppel stemming from America Invents Act (AIA) administrative trials (p. 20).
If a reissue claim is determined to be non-patentably distinct from a claim canceled or held finally unpatentable in an AIA trial, the examiner may issue an estoppel rejection separate from any prior art rejections. If the applicant presents arguments during prosecution that contradict a final holding of adverse judgment in an AIA trial, the examiner may determine those arguments are estopped and unpersuasive (p. 20).
Administrative Updates: Amendments and PTO/SB/57
When submitting amendments in either ex parte reexaminations or reissues, all changes must be formatted in relation to the issued patent. Practitioners must use underlining for additions and single brackets for deletions (p. 22). New claims require underlining in their entirety, and original claim numbering must be preserved.
The rules governing these mechanics are found in 37 CFR § 1.530(d), (f), and (g) for reexaminations, and 37 CFR § 1.173(b) for reissues. Both proceedings require practitioners to explicitly identify the support for the amendments within the original disclosure, governed by 37 CFR § 1.530(e) and § 1.173(c) respectively.
The USPTO updated the Request for Ex Parte Reexamination Transmittal Form (PTO/SB/57) in November 2025 to clarify anonymous filings. If a requester opts to remain anonymous, no requester should be identified in Box 2a (p. 31). The legal representative provides their name and address in Box 17. If the requester is identified, their information goes into Box 2b.
Benefits, Challenges, and Risks
Supplemental examination offers a strategic mechanism for patent owners to sanitize a patent file history prior to asserting the patent in litigation, neutralizing potential inequitable conduct threats. Correctly formatting reissue applications and ADSs expedites prosecution and prevents administrative delays at the Office. This administrative efficiency benefits patent owners seeking rapid claim adjustments ahead of impending litigation.
The strict requirements for SNQ identification pose a challenge, demanding higher precision from practitioners. Requesters cannot rely upon broad assertions of invalidity; they must perform granular comparative analysis between the prior art and the prosecution history to prove the teachings are non-cumulative. The administrative burdens of correct ADS filing and Patent Center selections create procedural friction that slows down prosecution preparation.
The risk of patent owner estoppel in reissue applications represents a severe hurdle. Patent owners attempting to salvage claims post-PTAB face immediate rejection if the new claims are not patentably distinct from those lost in an Inter Partes Review or Post Grant Review.
The Bauman application error presents a significant risk of abandoning intended reissue rights if not caught and petitioned in a timely manner. The financial and strategic costs of these errors are substantial, frequently resulting in a total loss of patent rights for specific embodiments.
Conclusion
The CRU demands rigorous adherence to procedural rules across all proceeding types. The distinction between a successful filing and a procedural rejection often rests on strict compliance with formatting, statutory declarations, and precise application data entry.
On a second look, two observations emerge from the recent USPTO slide deck guidance.
One observation is that the accelerated pace of the CRU—averaging two months for SNQ determinations—necessitates comprehensive, front-loaded preparation, as practitioners possess restricted flexibility for extensions once a proceeding initiates.
A second observation is that the increasing volume of filings, paired with new efficiency programs, suggests examiners will process actions faster, leaving a narrower margin for administrative errors.
This is all to say: stakeholders will watch to see if this pace continues and how it will affect CRU.
Patent professionals must integrate these technical directives into their filing protocols to maintain the enforceability and validity of intellectual property assets.
Disclaimer: This is provided for informational purposes only and does not constitute legal or financial advice. To the extent there are any opinions in this article, they are the author’s alone and do not represent the beliefs of his firm or clients. The strategies expressed are purely speculation based on publicly available information. The information expressed is subject to change at any time and should be checked for completeness, accuracy and current applicability. For advice, consult a suitably licensed attorney and/or patent professional.