37 CFR § 1.945 - Response to Office action by patent owner in reexamination.

---
identifier: "/us/cfr/t37/s1.945"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "37 CFR § 1.945 - Response to Office action by patent owner in  reexamination."
title_number: 37
title_name: "Patents, Trademarks, and Copyrights"
section_number: "1.945"
section_name: "Response to Office action by patent owner in  reexamination."
chapter_name: "UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE"
subchapter_number: "A"
subchapter_name: "GENERAL"
part_number: "1"
part_name: "RULES OF PRACTICE IN PATENT CASES"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "35 U.S.C. 2(b)(2), unless otherwise noted."
regulatory_source: "24 FR 10332, Dec. 22, 1959, unless otherwise noted."
cfr_part: "1"
---


# 1.945 Response to Office action by patent owner in  reexamination.

(a) The patent owner will be given at least thirty days to file a response to any Office action on the merits of the *inter partes* reexamination.

(b) Any supplemental response to the Office action will be entered only where the supplemental response is accompanied by a showing of sufficient cause why the supplemental response should be entered. The showing of sufficient cause must include:

(1) An explanation of how the requirements of § 1.111(a)(2)(i) are satisfied;

(2) An explanation of why the supplemental response was not presented together with the original response to the Office action; and

(3) A compelling reason to enter the supplemental response.

[72 FR 18906, Apr. 16, 2007]