Endangered Species Law & Policy

On November 21, 2025, the U.S. Fish & Wildlife Service and National Marine Fisheries Service (collectively, the Services) published several proposed rules to revise their regulations implementing certain provisions of the Endangered Species Act (ESA). To a substantial extent, the Services are proposing to return to the regulations put in place by the first Trump Administration in its prior rulemakings and thereby undo the changes put in place by the Biden Administration in its prior rulemakings. This is the third in a series of blog posts that will briefly describe each proposed rule. The notices state that the Services will accept comments on the proposed rules until December 22, 2025. A number of stakeholders have asked the Services to extend the comment deadline. As of this time, the Services have not done so.

In the third of the proposed rules, the Fish and Wildlife Service (FWS) proposes to remove the “blanket rule” option for protecting newly listed threatened species pursuant to section 4(d) of the ESA.

Section 4 of the ESA provides a process whereby the Secretary of Commerce or the Interior may list a species as threatened or endangered under the ESA. The distinction between threatened and endangered species is that the former is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range whereas the latter already is in danger of extinction throughout all or a significant portion of its range. Section 9 of the ESA delineates a specific list of prohibitions applicable to endangered species, but it does not automatically extend those same prohibitions to threatened species. However, section 4(d) authorizes the Services to, by regulation, prohibit with respect to any threatened species any act prohibited under section 9 for an endangered species. Such a regulation is commonly referred to as a 4(d) rule.

In 1978, FWS first promulgated blanket 4(d) rules, automatically applying nearly all the section 9 prohibitions that apply to endangered species to threatened species. These blanket 4(d) rules arguably turned Congressional intent on its head by requiring FWS to promulgate species-specific 4(d) rules to deviate from a default where threatened species were treated no differently than endangered species. Further, the National Marine Fisheries Service never followed suit and promulgated its own blanket 4(d) rules. In 2019, the Trump Administration removed the blanket rule option for newly listed species but continued to apply the blanket rule protections to species listed prior to the date of the final rule. In 2024, the Biden Administration reinstated the blanket rule.

The Services’ proposed rule would once again remove the blanket rule for newly listed species. As a consequence, FWS would be required to issue species-specific 4(d) rules. In the meantime, in a recent filing in a case brought by the American Farm Bureau Federation and others challenging the 2024 rule, FWS indicated that, during the rulemaking process, “whenever FWS proposes or finalizes the listing of a threatened species, it will concurrently address through rulemaking a species-specific Section 4(d) rule for that threatened species, including any Section 9(a) prohibitions for that species.” Therefore, as a practical matter, FWS is already behaving as if the blanket rule is no longer in place.