---
kind: "range"
citation: "37 C.F.R. §§ 1.510–1.560"
title: "37"
from: "1.510"
to: "1.560"
count: 11
url: "https://uscodex.org/cfr/37/1.510..1.560"
---

# §1.510. Request for ex parte reexamination.

- (a) Any person may, at any time during the period of enforceability of a patent, file a request for an ex parte reexamination by the Office of any claim of the patent on the basis of prior art patents or printed publications cited under [§ 1.501](/cfr/37/1.501.md), unless prohibited by 35 U.S.C. [315(e)(1)](/usc/35/315.md?p=e-1) or [35](/usc/35/35.md) U.S.C. 325(e)(1). The request must be accompanied by the fee for requesting reexamination set in [§ 1.20(c)(1)](/cfr/37/1.20.md?p=c-1).
- (b) Any request for reexamination must include the following parts:
  - (1) A statement pointing out each substantial new question of patentability based on prior patents and printed publications.
  - (2) An identification of every claim for which reexamination is requested, and a detailed explanation of the pertinency and manner of applying the cited prior art to every claim for which reexamination is requested. For each statement of the patent owner and accompanying information submitted pursuant to [§ 1.501(a)(2)](/cfr/37/1.501.md?p=a-2) which is relied upon in the detailed explanation, the request must explain how that statement is being used to determine the proper meaning of a patent claim in connection with the prior art applied to that claim and how each relevant claim is being interpreted. If appropriate, the party requesting reexamination may also point out how claims distinguish over cited prior art.
  - (3) A copy of every patent or printed publication relied upon or referred to in [paragraph (b)](#b) (1) and (2) of this section accompanied by an English language translation of all the necessary and pertinent parts of any non-English language patent or printed publication.
  - (4) A copy of the entire patent including the front face, drawings, and specification/claims (in double column format) for which reexamination is requested, and a copy of any disclaimer, certificate of correction, or reexamination certificate issued in the patent. All copies must have each page plainly written on only one side of a sheet of paper.
  - (5) A certification that a copy of the request filed by a person other than the patent owner has been served in its entirety on the patent owner at the address as provided for in [§ 1.33(c)](/cfr/37/1.33.md?p=c). The name and address of the party served must be indicated. If service was not possible, a duplicate copy must be supplied to the Office.
  - (6) A certification by the third party requester that the statutory estoppel provisions of 35 U.S.C. [315(e)(1)](/usc/35/315.md?p=e-1) or [35](/usc/35/35.md) U.S.C. 325(e)(1) do not prohibit the requester from filing the ex parte reexamination request.
- (c) If the request does not include the fee for requesting ex parte reexamination required by [paragraph (a)](#a) of this section and meet all the requirements by [paragraph (b)](#b) of this section, then the person identified as requesting reexamination will be so notified and will generally be given an opportunity to complete the request within a specified time. Failure to comply with the notice will result in the ex parte reexamination request not being granted a filing date, and will result in placement of the request in the patent file as a citation if it complies with the requirements of [§ 1.501](/cfr/37/1.501.md).
- (d) The filing date of the request for ex parte reexamination is the date on which the request satisfies all the requirements of this section.
- (e) A request filed by the patent owner may include a proposed amendment in accordance with [§ 1.530](/cfr/37/1.530.md).
- (f) If a request is filed by an attorney or agent identifying another party on whose behalf the request is being filed, the attorney or agent must have a power of attorney from that party or be acting in a representative capacity pursuant to [§ 1.34](/cfr/37/1.34.md).

# §1.515. Determination of the request for ex parte reexamination.

- (a) Within three months following the filing date of a request for an ex parte reexamination, an examiner will consider the request and determine whether or not a substantial new question of patentability affecting any claim of the patent is raised by the request and the prior art cited therein, with or without consideration of other patents or printed publications. A statement and any accompanying information submitted pursuant to [§ 1.501(a)(2)](/cfr/37/1.501.md?p=a-2) will not be considered by the examiner when making a determination on the request. The examiner's determination will be based on the claims in effect at the time of the determination, will become a part of the official file of the patent, and will be given or mailed to the patent owner at the address provided for in [§ 1.33(c)](/cfr/37/1.33.md?p=c) and to the person requesting reexamination.
- (b) Where no substantial new question of patentability has been found, a refund of a portion of the fee for requesting ex parte reexamination will be made to the requester in accordance with [§ 1.26(c)](/cfr/37/1.26.md?p=c).
- (c) The requester may seek review by a petition to the Director under [§ 1.181](/cfr/37/1.181.md) within one month of the mailing date of the examiner's determination refusing ex parte reexamination. Any such petition must comply with [§ 1.181(b)](/cfr/37/1.181.md?p=b). If no petition is timely filed or if the decision on petition affirms that no substantial new question of patentability has been raised, the determination shall be final and nonappealable.

# §1.520. Ex parte reexamination at the initiative of the Director.


The Director, at any time during the period of enforceability of a patent, may determine whether or not a substantial new question of patentability is raised by patents or printed publications which have been discovered by the Director or which have been brought to the Director's attention, even though no request for reexamination has been filed in accordance with [§ 1.510](/cfr/37/1.510.md) or [§ 1.913](/cfr/37/1.913.md). The Director may initiate ex parte reexamination without a request for reexamination pursuant to [§ 1.510](/cfr/37/1.510.md) or [§ 1.913](/cfr/37/1.913.md). Normally requests from outside the Office that the Director undertake reexamination on his own initiative will not be considered. Any determination to initiate ex parte reexamination under this section will become a part of the official file of the patent and will be mailed to the patent owner at the address as provided for in [§ 1.33(c)](/cfr/37/1.33.md?p=c).


# §1.525. Order for ex parte reexamination.

- (a) If a substantial new question of patentability is found pursuant to [§ 1.515](/cfr/37/1.515.md) or [§ 1.520](/cfr/37/1.520.md), the determination will include an order for ex parte reexamination of the patent for resolution of the question. If the order for ex parte reexamination resulted from a petition pursuant to [§ 1.515(c)](/cfr/37/1.515.md?p=c), the ex parte reexamination will ordinarily be conducted by an examiner other than the examiner responsible for the initial determination under [§ 1.515(a)](/cfr/37/1.515.md?p=a).
- (b) The notice published in the Official Gazette under [§ 1.11(c)](/cfr/37/1.11.md?p=c) will be considered to be constructive notice and ex parte reexamination will proceed.

# §1.530. Statement by patent owner in ex parte reexamination; amendment by patent owner in ex parte or inter partes reexamination; inventorship change in ex parte or inter partes reexamination.

- (a) Except as provided in [§ 1.510(e)](/cfr/37/1.510.md?p=e), no statement or other response by the patent owner in an ex parte reexamination proceeding shall be filed prior to the determinations made in accordance with [§ 1.515](/cfr/37/1.515.md) or [§ 1.520](/cfr/37/1.520.md). If a premature statement or other response is filed by the patent owner, it will not be acknowledged or considered in making the determination, and it will be returned or discarded (at the Office's option).
- (b) The order for ex parte reexamination will set a period of not less than two months from the date of the order within which the patent owner may file a statement on the new question of patentability, including any proposed amendments the patent owner wishes to make.
- (c) Any statement filed by the patent owner shall clearly point out why the subject matter as claimed is not anticipated or rendered obvious by the prior art patents or printed publications, either alone or in any reasonable combinations. Where the reexamination request was filed by a third party requester, any statement filed by the patent owner must be served upon the ex parte reexamination requester in accordance with [§ 1.248](/cfr/37/1.248.md).
- (d) **Making amendments in a reexamination proceeding.** A proposed amendment in an ex parte or an inter partes reexamination proceeding is made by filing a paper directing that proposed specified changes be made to the patent specification, including the claims, or to the drawings. An amendment paper directing that proposed specified changes be made in a reexamination proceeding may be submitted as an accompaniment to a request filed by the patent owner in accordance with [§ 1.510(e)](/cfr/37/1.510.md?p=e), as part of a patent owner statement in accordance with [paragraph (b)](#b) of this section, or, where permitted, during the prosecution of the reexamination proceeding pursuant to [§ 1.550(a)](/cfr/37/1.550.md?p=a) or [§ 1.937](/cfr/37/1.937.md).
  - (1) **Specification other than the claims, “Large Tables” (§ 1.58(c)), a “Computer Program Listing Appendix” (§ 1.96(c)), a “Sequence Listing” (§ 1.821(c)), or a “Sequence Listing XML (§ 1.831(a)).**
    - (i) Changes to the specification, other than to the claims, “Large Tables” ([§ 1.58(c)](/cfr/37/1.58.md?p=c)), a “Computer Program Listing Appendix” ([§ 1.96(c)](/cfr/37/1.96.md?p=c)), a “Sequence Listing” ([§ 1.821(c)](/cfr/37/1.821.md?p=c)), or a “Sequence Listing XML” ([§ 1.831(a)](/cfr/37/1.831.md?p=a)), must be made by submission of the entire text of an added or rewritten paragraph, including markings pursuant to [paragraph (f)](#f) of this section, except that an entire paragraph may be deleted by a statement deleting the paragraph, without presentation of the text of the paragraph. The precise point in the specification where any added or rewritten paragraph is located must be identified.
    - (ii) Changes to “Large Tables,” a “Computer Program Listing Appendix,” a “Sequence Listing,” or a “Sequence Listing XML” must be made in accordance with [§ 1.58(g)](/cfr/37/1.58.md?p=g) for “Large Tables,” [§ 1.96(c)(5)](/cfr/37/1.96.md?p=c-5) for a “Computer Program Listing Appendix,” [§ 1.825](/cfr/37/1.825.md) for a “Sequence Listing,” or [§ 1.835](/cfr/37/1.835.md) for a “Sequence Listing XML.”
  - (2) **Claims.** An amendment paper must include the entire text of each patent claim which is being proposed to be changed by such amendment paper and of each new claim being proposed to be added by such amendment paper. For any claim changed by the amendment paper, a parenthetical expression “amended,” “twice amended,” etc., should follow the claim number. Each patent claim proposed to be changed and each proposed added claim must include markings pursuant to [paragraph (f)](#f) of this section, except that a patent claim or proposed added claim should be canceled by a statement canceling the claim, without presentation of the text of the claim.
  - (3) **Drawings.** Any change to the patent drawings must be submitted as a sketch on a separate paper showing the proposed changes in red for approval by the examiner. Upon approval of the changes by the examiner, only new sheets of drawings including the changes and in compliance with [§ 1.84](/cfr/37/1.84.md) must be filed. Amended figures must be identified as “Amended,” and any added figure must be identified as “New.” In the event a figure is canceled, the figure must be surrounded by brackets and identified as “Canceled.”
  - (4) The formal requirements for papers making up the reexamination proceeding other than those set forth in this section are set out in [§ 1.52](/cfr/37/1.52.md).
- (e) **Status of claims and support for claim changes.** Whenever there is an amendment to the claims pursuant to [paragraph (d)](#d) of this section, there must also be supplied, on pages separate from the pages containing the changes, the status (i.e., pending or canceled), as of the date of the amendment, of all patent claims and of all added claims, and an explanation of the support in the disclosure of the patent for the changes to the claims made by the amendment paper.
- (f) **Changes shown by markings.** Any changes relative to the patent being reexamined which are made to the specification, including the claims, must include the following markings:
  - (1) The matter to be omitted by the reexamination proceeding must be enclosed in brackets; and
  - (2) The matter to be added by the reexamination proceeding must be underlined.
- (g) **Numbering of patent claims preserved.** Patent claims may not be renumbered. The numbering of any claims added in the reexamination proceeding must follow the number of the highest numbered patent claim.
- (h) **Amendment of disclosure may be required.** The disclosure must be amended, when required by the Office, to correct inaccuracies of description and definition, and to secure substantial correspondence between the claims, the remainder of the specification, and the drawings.
- (i) **Amendments made relative to patent.** All amendments must be made relative to the patent specification, including the claims, and drawings, which are in effect as of the date of filing the request for reexamination.
- (j) **No enlargement of claim scope.** No amendment may enlarge the scope of the claims of the patent or introduce new matter. No amendment may be proposed for entry in an expired patent. Moreover, no amendment, other than the cancellation of claims, will be incorporated into the patent by a certificate issued after the expiration of the patent.
- (k) **Amendments not effective until certificate.** Although the Office actions will treat proposed amendments as though they have been entered, the proposed amendments will not be effective until the reexamination certificate is issued and published.
- (l) **Correction of inventorship in an ex parte or inter partes reexamination proceeding.**
  - (1) When it appears in a patent being reexamined that the correct inventor or inventors were not named, the Director may, on petition of all the parties set forth in § [1.324(b)(1)](/cfr/37/1.324.md?p=b-1) and [(b)(2)](/cfr/37/1.324.md?p=b-2), including the assignees, and satisfactory proof of the facts and payment of the fee set forth in [§ 1.20(b)](/cfr/37/1.20.md?p=b), or on order of a court before which such matter is called in question, include in the reexamination certificate to be issued under [§ 1.570](/cfr/37/1.570.md) or [§ 1.997](/cfr/37/1.997.md) an amendment naming only the actual inventor or inventors. The petition must be submitted as part of the reexamination proceeding and must satisfy the requirements of [§ 1.324](/cfr/37/1.324.md).
  - (2) Notwithstanding [paragraph (l)(1)](#l-1) of this section, if a petition to correct inventorship satisfying the requirements of [§ 1.324](/cfr/37/1.324.md) is filed in a reexamination proceeding, and the reexamination proceeding is concluded other than by a reexamination certificate under [§ 1.570](/cfr/37/1.570.md) or [§ 1.997](/cfr/37/1.997.md), a certificate of correction indicating the change of inventorship stated in the petition will be issued upon request by the patentee.

# §1.535. Reply by third party requester in ex parte reexamination.


A reply to the patent owner's statement under [§ 1.530](/cfr/37/1.530.md) may be filed by the ex parte reexamination requester within two months from the date of service of the patent owner's statement. Any reply by the ex parte requester must be served upon the patent owner in accordance with [§ 1.248](/cfr/37/1.248.md). If the patent owner does not file a statement under [§ 1.530](/cfr/37/1.530.md), no reply or other submission from the ex parte reexamination requester will be considered.


# §1.540. Consideration of responses in ex parte reexamination.


The failure to timely file or serve the documents set forth in [§ 1.530](/cfr/37/1.530.md) or in [§ 1.535](/cfr/37/1.535.md) may result in their being refused consideration. No submissions other than the statement pursuant to [§ 1.530](/cfr/37/1.530.md) and the reply by the ex parte reexamination requester pursuant to [§ 1.535](/cfr/37/1.535.md) will be considered prior to examination.


# §1.550. Conduct of ex parte reexamination proceedings.

- (a) All ex parte reexamination proceedings, including any appeals to the Board of Patent Appeals and Interferences, will be conducted with special dispatch within the Office. After issuance of the ex parte reexamination order and expiration of the time for submitting any responses, the examination will be conducted in accordance with [§§ 1.104 through 1.116](/cfr/37/1.104..1.116.md) and will result in the issuance of an ex parte reexamination certificate under [§ 1.570](/cfr/37/1.570.md).
- (b) The patent owner in an ex parte reexamination proceeding will be given at least thirty days to respond to any Office action. In response to any rejection, such response may include further statements and/or proposed amendments or new claims to place the patent in a condition where all claims, if amended as proposed, would be patentable.
- (c) The time for taking any action by a patent owner in an ex parte reexamination proceeding may be extended as provided in this paragraph.
  - (1) Any request for such an extension must specify the requested period of extension and be accompanied by the petition fee set forth in [§ 1.17(g)](/cfr/37/1.17.md?p=g).
  - (2) Any request for an extension in a third party requested ex parte reexamination must be filed on or before the day on which action by the patent owner is due, and the mere filing of such a request for extension will not effect the extension. A request for an extension in a third party requested ex parte reexamination will not be granted in the absence of sufficient cause or for more than a reasonable time.
  - (3) Any request for an extension in a patent owner requested or Director ordered ex parte reexamination for up to two months from the time period set in the Office action must be filed no later than two months from the expiration of the time period set in the Office action. A request for an extension in a patent owner requested or Director ordered ex parte reexamination for more than two months from the time period set in the Office action must be filed on or before the day on which action by the patent owner is due, and the mere filing of a request for an extension for more than two months from the time period set in the Office action will not effect the extension. The time for taking action in a patent owner requested or Director ordered ex parte reexamination will not be extended for more than two months from the time period set in the Office action in the absence of sufficient cause or for more than a reasonable time.
  - (4) The reply or other action must in any event be filed prior to the expiration of the period of extension, but in no situation may a reply or other action be filed later than the maximum time period set by statute.
  - (5) See [§ 90.3(c)](/cfr/37/90.3.md?p=c) of this title for extensions of time for filing a notice of appeal to the U.S. Court of Appeals for the Federal Circuit or for commencing a civil action.
- (d) If the patent owner fails to file a timely and appropriate response to any Office action or any written statement of an interview required under [§ 1.560(b)](/cfr/37/1.560.md?p=b), the prosecution in the ex parte reexamination proceeding will be a terminated prosecution, and the Director will proceed to issue and publish a certificate concluding the reexamination proceeding under [§ 1.570](/cfr/37/1.570.md) in accordance with the last action of the Office.
- (e) If a response by the patent owner is not timely filed in the Office, a petition may be filed pursuant to [§ 1.137](/cfr/37/1.137.md) to revive a reexamination prosecution terminated under [paragraph (d)](#d) of this section if the delay in response was unintentional.
- (f) The reexamination requester will be sent copies of Office actions issued during the ex parte reexamination proceeding. After filing of a request for ex parte reexamination by a third party requester, any document filed by either the patent owner or the third party requester must be served on the other party in the reexamination proceeding in the manner provided by [§ 1.248](/cfr/37/1.248.md). The document must reflect service or the document may be refused consideration by the Office.
- (g) The active participation of the ex parte reexamination requester ends with the reply pursuant to [§ 1.535](/cfr/37/1.535.md), and no further submissions on behalf of the reexamination requester will be acknowledged or considered. Further, no submissions on behalf of any third parties will be acknowledged or considered unless such submissions are:
  - (1) in accordance with [§ 1.510](/cfr/37/1.510.md) or [§ 1.535](/cfr/37/1.535.md); or
  - (2) entered in the patent file prior to the date of the order for ex parte reexamination pursuant to [§ 1.525](/cfr/37/1.525.md).
- (h) Submissions by third parties, filed after the date of the order for ex parte reexamination pursuant to [§ 1.525](/cfr/37/1.525.md), must meet the requirements of and will be treated in accordance with [§ 1.501(a)](/cfr/37/1.501.md?p=a).
- (i) A petition in an ex parte reexamination proceeding must be accompanied by the fee set forth in [§ 1.20(c)(6)](/cfr/37/1.20.md?p=c-6), except for petitions under [paragraph (c)](#c) of this section to extend the period for response by a patent owner, petitions under [paragraph (e)](#e) of this section to accept a delayed response by a patent owner, petitions under [§ 1.78](/cfr/37/1.78.md) to accept an unintentionally delayed benefit claim, and petitions under [§ 1.530(l)](/cfr/37/1.530.md?p=l) for correction of inventorship in a reexamination proceeding.

# §1.552. Scope of reexamination in ex parte reexamination proceedings.

- (a) Claims in an ex parte reexamination proceeding will be examined on the basis of patents or printed publications and, with respect to subject matter added or deleted in the reexamination proceeding, on the basis of the requirements of [35 U.S.C. 112](/usc/35/112.md).
- (b) Claims in an ex parte reexamination proceeding will not be permitted to enlarge the scope of the claims of the patent.
- (c) Issues other than those indicated in paragraphs [(a)](#a) and [(b)](#b) of this section will not be resolved in a reexamination proceeding. If such issues are raised by the patent owner or third party requester during a reexamination proceeding, the existence of such issues will be noted by the examiner in the next Office action, in which case the patent owner may consider the advisability of filing a reissue application to have such issues considered and resolved.
- (d) Any statement of the patent owner and any accompanying information submitted pursuant to [§ 1.501(a)(2)](/cfr/37/1.501.md?p=a-2) which is of record in the patent being reexamined (which includes any reexamination files for the patent) may be used after a reexamination proceeding has been ordered to determine the proper meaning of a patent claim when applying patents or printed publications.

# §1.555. Information material to patentability in ex parte reexamination and inter partes reexamination proceedings.

- (a) **A patent by its very nature is affected with a public interest.** The public interest is best served, and the most effective reexamination occurs when, at the time a reexamination proceeding is being conducted, the Office is aware of and evaluates the teachings of all information material to patentability in a reexamination proceeding. Each individual associated with the patent owner in a reexamination proceeding has a duty of candor and good faith in dealing with the Office, which includes a duty to disclose to the Office all information known to that individual to be material to patentability in a reexamination proceeding. The individuals who have a duty to disclose to the Office all information known to them to be material to patentability in a reexamination proceeding are the patent owner, each attorney or agent who represents the patent owner, and every other individual who is substantively involved on behalf of the patent owner in a reexamination proceeding. The duty to disclose the information exists with respect to each claim pending in the reexamination proceeding until the claim is cancelled. Information material to the patentability of a cancelled claim need not be submitted if the information is not material to patentability of any claim remaining under consideration in the reexamination proceeding. The duty to disclose all information known to be material to patentability in a reexamination proceeding is deemed to be satisfied if all information known to be material to patentability of any claim in the patent after issuance of the reexamination certificate was cited by the Office or submitted to the Office in an information disclosure statement. However, the duties of candor, good faith, and disclosure have not been complied with if any fraud on the Office was practiced or attempted or the duty of disclosure was violated through bad faith or intentional misconduct by, or on behalf of, the patent owner in the reexamination proceeding. Any information disclosure statement must be filed with the items listed in [§ 1.98(a)](/cfr/37/1.98.md?p=a) as applied to individuals associated with the patent owner in a reexamination proceeding, should be filed within two months of the date of the order for reexamination, or as soon thereafter as possible, and be accompanied by any applicable information disclosure statement size fee under [§ 1.17(v)](/cfr/37/1.17.md?p=v).
- (b) Under this section, information is material to patentability in a reexamination proceeding when it is not cumulative to information of record or being made of record in the reexamination proceeding, and
  - (1) It is a patent or printed publication that establishes, by itself or in combination with other patents or printed publications, a prima facie case of unpatentability of a claim; or
  - (2) **It refutes, or is inconsistent with, a position the patent owner takes in—**
    - (i) Opposing an argument of unpatentability relied on by the Office, or
    - (ii) **Asserting an argument of patentability.**
- (c) The responsibility for compliance with this section rests upon the individuals designated in [paragraph (a)](#a) of this section and no evaluation will be made by the Office in the reexamination proceeding as to compliance with this section. If questions of compliance with this section are raised by the patent owner or the third party requester during a reexamination proceeding, they will be noted as unresolved questions in accordance with [§ 1.552(c)](/cfr/37/1.552.md?p=c).

# §1.560. Interviews in ex parte reexamination proceedings.

- (a) Interviews in ex parte reexamination proceedings pending before the Office between examiners and the owners of such patents or their attorneys or agents of record must be conducted in the Office at such times, within Office hours, as the respective examiners may designate. Interviews will not be permitted at any other time or place without the authority of the Director. Interviews for the discussion of the patentability of claims in patents involved in ex parte reexamination proceedings will not be conducted prior to the first official action. Interviews should be arranged in advance. Requests that reexamination requesters participate in interviews with examiners will not be granted.
- (b) In every instance of an interview with an examiner in an ex parte reexamination proceeding, a complete written statement of the reasons presented at the interview as warranting favorable action must be filed by the patent owner. An interview does not remove the necessity for response to Office actions as specified in [§ 1.111](/cfr/37/1.111.md). Patent owner's response to an outstanding Office action after the interview does not remove the necessity for filing the written statement. The written statement must be filed as a separate part of a response to an Office action outstanding at the time of the interview, or as a separate paper within one month from the date of the interview, whichever is later.