Feds Repeal Regulatory Definition Of "Harm” Under Endangered Species Act

Regulatory Definition

By John M. Simpson. On July 14, 2026, the U.S. Fish and Wildlife Service and the National Marine Fisheries Service (collectively, the “Services”) published a final rule rescinding the longstanding regulatory definition of “harm” under the Endangered Species Act. The rescission removes the definition from 50 CFR Parts 17 and 222, effectively ending the decades-old practice of treating significant habitat modification or degradation as a form of prohibited “take” under Section 9 of the ESA. The rule represents one of the most consequential reinterpretations of the ESA in the statute’s history.

What the Rule Does

Since 1975, FWS’s regulatory definition of “harm” had included habitat modification within the meaning of “take.” The 1981 revision narrowed the definition somewhat, requiring that habitat modification “actually kills or injures wildlife by significantly impairing essential behavioral patterns, including breeding, feeding or sheltering.” NMFS adopted a