New USPTO Disclosure Requirements for Ex Parte Reexamination Requests
The USPTO has issued proposed new rules, 91 FR 46038 (July 22, 2026), to require ex parte reexamination requests to include a statement of the real party in interest. This comes on the heels of guidance issued in February on filing anonymous requests for ex parte reexamination, such as through a registered practitioner. The earlier guidance included a reminder that submitting a request for ex parte reexamination involved a certification that the requester was not subject to the statutory estoppel provisions regarding prior inter partes reviews and post-grant reviews of that patent (in 35 USC 315(e)(1) and 325(e)(1), respectively). The February guidance emphasized that the certification included a certification for not just the requester, but also for any real party in interest. Now the USPTO has gone a step further, to require disclosure of the real party in interest as part of an ex parte reexamination request.
Requests for ex parte reexamination (reexamination of issued patents by the USPTO based on prior art, generally prior art that was not considered in the initial examination) may be filed by “[a]ny person at any time,” 35 USC 302. There is a provision that allows the identity of those who submit prior art to remain confidential, 35 USC 301(e), and practitioners have often submitted ex parte reexamination requests in their own names, shielding the identity of patent challengers.
The USPTO has in the last year taken a series of actions to curb post-issuance challenges. Last fall the USPTO proposed rules that would greatly increase the estoppel effect of inter partes reviews, essentially limiting patent challengers to one validity challenge, either at the USPTO or in litigation. See90 FR 48335 (Oct. 17, 2025). (See also my piece on the proposed rules, and Renner Otto’s submitted comments on these proposed rules.) In addition Director Squires increasingly has used his discretion to deny post-grant inter partes patent challenges. See, e.g.,this piece.
This caused a shift to use of ex parte reexaminations as a vehicle for challenging patents. But a request for reexamination must include a certification that the requester is not prohibited from filing such a request due to estoppel arising from a prior inter partes review of post-grant review. 37 CFR 1.510(b)(6). As the MPEP states, the estoppel provisions “only prohibit the filing of a subsequent request for ex parte reexamination, once estoppel attaches; there is no estoppel as to the Office maintaining an existing ex parte reexamination proceeding.” MPEP 2210.
The February guidance made clear that the estoppel provisions apply to real parties in interest, such as those behind an ex parte reexamination request filed by a third-party practitioner. Now the USPTO is seeking to require disclosure of the real parties in interest behind ex parte reexamination requests in a new provision, 37 CFR 1.510(b)(7). The rationale for this new rule is to allow the USPTO to better ascertain when estoppel applied, such as when considering petitions by patent owner disputing the requester’s certification under 37 CFR 1.510(b)(6). This rule had been previously proposed in 2012, but was not adopted. See 77 FR 46615 (Aug. 6, 2012).
The proposed new rules would allow the requester to request that the disclosure of real party in interest be kept confidential, in which would case the information would be not be available to the general public (though the USPTO would have access to it). As far as what constitutes a real party in interest, the proposed rule announcement admits that this is “a highly fact-dependent question that is determined on a case-by-case basis,” and provides citations to case law and to Section I(D)(1) of the USPTO’s Consolidated Trial Practice Guide.
One concern about the new proposed rules is that it might have “a chilling effect on the submission of ex parte reexamination requests,” as was noted in a number of comments that led to the rule not being adopted when proposed in 2012. See 77 FR at 44621. But given the USPTO’s efforts to protect issued patents from challenges, adoption of the proposed new rules is expected.
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