50 CFR § 424.21 - Periodic review.

---
identifier: "/us/cfr/t50/s424.21"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "50 CFR § 424.21 - Periodic review."
title_number: 50
title_name: "Wildlife and Fisheries"
section_number: "424.21"
section_name: "Periodic review."
chapter_name: "JOINT REGULATIONS (UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR AND NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE); ENDANGERED SPECIES COMMITTEE REGULATIONS"
subchapter_number: "A"
subchapter_name: "SUBCHAPTER A"
part_number: "424"
part_name: "LISTING ENDANGERED AND THREATENED SPECIES AND DESIGNATING CRITICAL HABITAT"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "16 U.S.C. 1531"
regulatory_source: "49 FR 38908, Oct. 1, 1984, unless otherwise noted."
cfr_part: "424"
---


# 424.21 Periodic review.

At least once every 5 years, the Secretary shall conduct a review of each listed species to determine whether it should be delisted or reclassified. Each such determination shall be made in accordance with §§ 424.11, 424.16, and 424.17 of this part, as appropriate. A notice announcing those species under active review will be published in the *Federal Register.* Notwithstanding this section's provisions, the Secretary may review the status of any species at any time based upon a petition (see § 424.14) or upon other data available to the Service.