37 CFR § 1.913 - Persons eligible to file, and time for filing, a request for reexamination.
---
identifier: "/us/cfr/t37/s1.913"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "37 CFR § 1.913 - Persons eligible to file, and time for filing, a request for reexamination."
title_number: 37
title_name: "Patents, Trademarks, and Copyrights"
section_number: "1.913"
section_name: "Persons eligible to file, and time for filing, a request for 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: "2026-03-24"
last_updated: "2026-03-24"
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"
---
# 1.913 Persons eligible to file, and time for filing, a request for reexamination.
(a) Except as provided for in § 1.907 and in paragraph (b) of this section, any person other than the patent owner or its privies may, at any time during the period of enforceability of a patent which issued from an original application filed in the United States on or after November 29, 1999, file a request for *inter partes* reexamination by the Office of any claim of the patent on the basis of prior art patents or printed publications cited under § 1.501.
(b) Any request for an *inter partes* reexamination submitted on or after September 16, 2012, will not be accorded a filing date, and any such request will not be granted.
[76 FR 59057, Sept. 23, 2011]