Under section 4(d) of the Endangered Species Act (ESA), the Secretary of Commerce (Secretary) shall issue regulations they deem necessary and advisable for the conservation of species listed as threatened. The Secretary may also apply any of the prohibitions in section 9(a)(1) of the ESA, including prohibiting import, export, take, and interstate commerce. This proposed ESA 4(d) rule would issue regulations for the threatened Banggai cardinalfish (Pterapogon kauderni). On March 29, 2021, we published a notice announcing the initiation of a 5-year review of the Banggai cardinalfish and requested information on the species, particularly information on the status, threats, and recovery of the species that has become available since its listing (86 FR 16326). The five-year review was completed on October 28, 2021, and is posted on our website (https://www.fisheries.noaa.gov/resource/document/banggai-cardinalfish-5-year-review). On April 22, 2021, we received a petition from the Center for Biological Diversity, Animal Welfare Institute, and the Defenders of Wildlife requesting we promulgate a rule under section 4(d) of the ESA to provide for the conservation of the Banggai cardinalfish. We published a notice of receipt of the petition and request for comments, on August 4, 2021 (86 FR 41935).