MPEP 2284
Copending Ex Parte Reexamination and Interference Proceedings

Ninth Edition of the MPEP, Revision 07.2022, Last Revised in February 2023

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2284    Copending Ex Parte Reexamination and Interference Proceedings [R-10.2019]

37 C.F.R. 1.565 Concurrent office proceedings which include an ex parte reexamination proceeding.

  • (a) In an ex parte reexamination proceeding before the Office, the patent owner must inform the Office of any prior or concurrent proceedings in which the patent is or was involved such as interferences, reissues, ex parte reexaminations, inter partes reexaminations, or litigation and the results of such proceedings. See § 1.985 for notification of prior or concurrent proceedings in an inter partes reexamination proceeding.


  • (e) If a patent in the process of ex parte reexamination is or becomes involved in an interference, the Director may suspend the reexamination or the interference. The Director will not consider a request to suspend an interference unless a motion (§ 41.121(a)(3) of this title) to suspend the interference has been presented to, and denied by, an administrative patent judge, and the request is filed within ten (10) days of a decision by an administrative patent judge denying the motion for suspension or such other time as the administrative patent judge may set. For concurrent inter partes reexamination and interference of a patent, see § 1.993.

37 C.F.R. 41.8 Mandatory notices.

  • (a) In an appeal brief (§§ 41.37, 41.67, or 41.68 ) or at the initiation of a contested case (§ 41.101 ), and within 20 days of any change during the proceeding, a party must identify:
    • (1) Its real party-in-interest, and
    • (2) Each judicial or administrative proceeding that could affect, or be affected by, the Board proceeding.
  • (b) For contested cases, a party seeking judicial review of a Board proceeding must file a notice with the Board of the judicial review within 20 days of the filing of the complaint or the notice of appeal. The notice to the Board must include a copy of the complaint or notice of appeal. See also §§ 1.301 to1.304 of this title.

37 C.F.R. 41.102 Completion of examination.

Before a contested case is initiated, except as the Board may otherwise authorize, for each involved application and patent:

  • (a) Examination or reexamination must be completed, and
  • (b) There must be at least one claim that:
    • (1) Is patentable but for a judgment in the contested case, and
    • (2) Would be involved in the contested case.

37 C.F.R. 41.103 Jurisdiction over involved files.

The Board acquires jurisdiction over any involved file when the Board initiates a contested case. Other proceedings for the involved file within the Office are suspended except as the Board may order.

A patent being reexamined in an ex parte reexamination proceeding may be involved in an interference proceeding with at least one application, where the patent and the application are claiming the same patentable invention, and at least one of the application’s claims to that invention are patentable to the applicant. See MPEP Chapter 2300.

The general policy of the Office is that a reexamination proceeding will not be delayed, or stayed, because of an interference or the possibility of an interference. The reason for this policy is the requirement of 35 U.S.C. 305 that all reexamination proceedings be conducted with "special dispatch" within the Office. In general, the Office will follow the practice of making the required and necessary decisions in the reexamination proceeding and, at the same time, going forward with the interference to the extent desirable. It is noted that 37 CFR 41.103 provides the Board with the flexibility to tailor a specific solution to occurrences where reexamination and interference proceedings for the same patent are copending, as such occurrences may arise. Decisions in the interference will take into consideration the status of the reexamination proceeding and what is occurring therein. The decision as to what actions are taken in the interference will, in general, be taken in accordance with normal interference practice.

Although a patent being reexamined via a reexamination proceeding may become involved in an interference proceeding, the reexamination proceeding itself can never be involved in an interference proceeding. See 35 U.S.C. 135 subsection (a) which states that "[w]henever an application is made for a patent which, in the opinion of the Director, would interfere with any pending application, or with any unexpired patent, an interference may be declared" (emphasis added). The reexamination proceeding is neither an application nor a patent.


When an amendment is filed in a pending application seeking to provoke an interference with a patent involved in a reexamination proceeding, the applicant must comply with 37 CFR 41.202(a), including identifying the patent under reexamination with which interference is sought. The corresponding application claims may be rejected on any applicable ground including, if appropriate, the prior art cited in the reexamination proceeding. See MPEP Chapter 2300. Prosecution of the application should continue as far as possible. If the application is placed in condition for allowance and still contains claims which interfere with claims of the patent under reexamination, then an interference should ordinarily be proposed between the application and the patent. The examiner must notify the Office of Patent Legal Administration (OPLA) before proposing the interference, and such an interference may not be proposed unless authorized by OPLA.

If the interference is not authorized (e.g., resolution of an issue in the reexamination proceeding is necessary to the interference), further action on the application should be suspended until the certificate on the reexamination proceeding has been issued and published.

Once the reexamination certificate has issued and published, the examiner should review the certificate to see if it makes any changes in the patent claims and then evaluate whether the patent still contains claims which interfere with claims of the application. If the claims do interfere, then the examiner should propose an interference. See MPEP Chapter 2300.


A miscellaneous motion under 37 CFR 41.121(a)(3) to suspend an interference pending the outcome of a reexamination proceeding may be made at any time during the interference by any party thereto. See 37 CFR 41.123(b) for the procedure. The motion must be presented to the administrative patent judge who will decide the motion based on the particular fact situation. However, suspension is not favored. Normally, no consideration will be given such a motion unless and until a reexamination order is issued, nor will suspension of the interference normally be permitted until after any motions have been disposed of in the interference proceeding. If the motion under 37 CFR 41.121(a)(3) is denied by the administrative patent judge, a request to stay the interference may be made to the Director of the USPTO under 37 CFR 1.565(e).

A request to stay an interference under 37 CFR 1.565(e) will be decided by the Chief Administrative Patent Judge of the Board.


In view of the provisions of 37 CFR 1.510(a), "[a]ny person may, at any time during the period of enforceability of a patent" file a request for reexamination. Under 37 CFR 41.8(a), the patent owner must notify the Board that a request for reexamination was filed, within 20 days of receiving notice of the request having been filed. Where it is the patent owner that files the request for reexamination, the 20 days run from the filing date of the request, since that is when the patent owner "received the notice" of filing the request. Such requests for reexamination will be processed in the normal manner. No delay, or stay, of the reexamination will occur because the requester is not a party to the interference. If the examiner orders reexamination pursuant to 37 CFR 1.525 and subsequently rejects a patent claim corresponding to a count in the interference, the attention of the Board shall be called thereto.


Under 37 CFR 1.565, the patent owner in a reexamination proceeding before the Office is required to notify the Office when the patent being reexamined becomes involved in an interference. To do so, the patent owner must file in the reexamination proceeding a paper giving notice of the interference proceeding. The requirements of 37 CFR 1.565, and of 37 CFR 41.8(a) (see the preceding paragraph), are designed to keep the Office and the appropriate parties informed of activity which is relevant to reexamination and interference proceedings and, to the extent possible, to eliminate procedural surprise.


Any petition to stay a reexamination proceeding, because of an interference, which is filed prior to the determination (37 CFR 1.515 ) and order to reexamine (37 CFR 1.525 ) will not be considered, but will be returned to the party submitting the same. The decision returning such a premature petition will be made of record in the reexamination file, but no copy of the petition will be retained by the Office. A petition to stay the reexamination proceeding because of the interference may be filed by the patent owner as a part of the patent owner’s statement under 37 CFR 1.530 or subsequent thereto. If a party to the interference, other than the patent owner, is a requester of the reexamination, that party may petition to stay the reexamination proceeding as a part of a reply pursuant to 37 CFR 1.535. If the other party to the interference is not the requester, any petition by that party is improper under 37 CFR 1.550(g) and will not be considered. Any such improper petitions will be returned to the party submitting the same. Premature petitions to stay the reexamination proceedings, i.e., those filed prior to the determination (37 CFR 1.515 ) and order to reexamine (37 CFR 1.525 ), will be returned by the Central Reexamination Unit (CRU) or Technology Center (TC) Director as premature. Petitions to stay filed subsequent to the date of the order for reexamination will be referred to OPLA for decision. All decisions on the merits of petitions to stay a reexamination proceeding because of an interference will be made in OPLA.


If one or more claims of a patent which is involved in an interference are canceled or amended by the issuance and publication of a reexamination certificate, the Board must be promptly notified.

Upon issuance and publication of the reexamination certificate, the patent owner must notify the administrative patent judge thereof.