37 C.F.R. § 1.137 : Patents, Trademarks, and Copyrights — UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE — GENERAL — RULES OF PRACTICE IN PATENT CASES — NATIONAL PROCESSING PROVISIONS —TIME FOR REPLY BY APPLICANT; ABANDONMENT OF APPLICATION — Revival of abandoned application, or terminated or limited reexamination prosecution

(a) Revival on the basis of unintentional delay. If the delay in reply by applicant or patent owner was unintentional, a petition may be filed pursuant to this section to revive an abandoned application or a reexamination prosecution terminated under §1.550(d) or §1.957(b) or limited under §1.957(c).
(b) Petition requirements. A grantable petition pursuant to this section must be accompanied by:
(1) The reply required to the outstanding Office action or notice, unless previously filed;
(2) The petition fee as set forth in §1.17(m);
(3) Any terminal disclaimer (and fee as set forth in §1.20(d)) required pursuant to paragraph (d) of this section; and
(4) A statement that the entire delay in filing the required reply from the due date for the reply until the filing of a grantable petition pursuant to this section was unintentional. The Director may require additional information where there is a question whether the delay was unintentional.
(c) Reply. In an application abandoned under §1.57(a), the reply must include a copy of the specification and any drawings of the previously filed application. In an application or patent abandoned for failure to pay the issue fee or any portion thereof, the required reply must include payment of the issue fee or any outstanding balance. In an application abandoned for failure to pay the publication fee, the required reply must include payment of the publication fee. In a nonprovisional application abandoned for failure to prosecute, the required reply may be met by the filing of a continuing application. In a nonprovisional utility or plant application filed on or after June 8, 1995, abandoned after the close of prosecution as defined in §1.114(b), the required reply may also be met by the filing of a request for continued examination in compliance with §1.114.
(d) Terminal disclaimer.
(1) Any petition to revive pursuant to this section in a design application must be accompanied by a terminal disclaimer and fee as set forth in §1.321 dedicating to the public a terminal part of the term of any patent granted thereon equivalent to the period of abandonment of the application. Any petition to revive pursuant to this section in either a utility or plant application filed before June 8, 1995, must be accompanied by a terminal disclaimer and fee as set forth in §1.321 dedicating to the public a terminal part of the term of any patent granted thereon equivalent to the lesser of:
(i) The period of abandonment of the application; or
(ii) The period extending beyond twenty years from the date on which the application for the patent was filed in the United States or, if the application contains a specific reference to an earlier filed application(s) under 35 U.S.C. 120, 121, 365(c), or 386(c) from the date on which the earliest such application was filed.
(2) Any terminal disclaimer pursuant to paragraph (d)(1) of this section must also apply to any patent granted on a continuing utility or plant application filed before June 8, 1995, or a continuing design application, that contains a specific reference under 35 U.S.C. 120, 121, 365(c), or 386(c) to the application for which revival is sought.
(3) The provisions of paragraph (d)(1) of this section do not apply to applications for which revival is sought solely for purposes of copendency with a utility or plant application filed on or after June 8, 1995, to reissue applications, or to reexamination proceedings.
(e) Request for reconsideration. Any request for reconsideration or review of a decision refusing to revive an abandoned application, or a terminated or limited reexamination prosecution, upon petition filed pursuant to this section, to be considered timely, must be filed within two months of the decision refusing to revive or within such time as set in the decision. Unless a decision indicates otherwise, this time period may be extended under:
(1) The provisions of §1.136 for an abandoned application;
(2) The provisions of §1.550(c) for a terminated ex parte reexamination prosecution, where the ex parte reexamination was filed under §1.510; or
(3) The provisions of §1.956 for a terminated inter partes reexamination prosecution or an inter partes reexamination limited as to further prosecution, where the inter partes reexamination was filed under §1.913.
(f) Abandonment for failure to notify the Office of a foreign filing. A nonprovisional application abandoned pursuant to 35 U.S.C. 122(b)(2)(B)(iii) for failure to timely notify the Office of the filing of an application in a foreign country or under a multinational treaty that requires publication of applications eighteen months after filing, may be revived pursuant to this section. The reply requirement of paragraph (c) of this section is met by the notification of such filing in a foreign country or under a multinational treaty, but the filing of a petition under this section will not operate to stay any period for reply that may be running against the application.
(g) Provisional applications. A provisional application, abandoned for failure to timely respond to an Office requirement, may be revived pursuant to this section. Subject to the provisions of 35 U.S.C. 119(e)(3) and § 1.7 (b), a provisional application will not be regarded as pending after twelve months from its filing date under any circumstances.

37 C.F.R. §1.137

78 FR 62405, 10/21/2013, as amended at 80 FR 17963, 4/2/2015