What to Know
- FWS and NMFS rescinded the ESA’s regulatory definition of “harm,” effective September 12, 2026.
- Habitat modification alone no longer counts as prohibited “take” under the new interpretation.
- The rule applies only prospectively, so existing permits and take statements won’t be reevaluated.
On July 14, 2026, the US Fish and Wildlife Service (FWS) and National Marine Fisheries Service (NMFS) (collectively, the Services) published a final rule rescinding the regulatory definition of “harm” under the Endangered Species Act (ESA). The Services did not promulgate a substitute definition but instead announced that moving forward they will rely solely on the ESA statutory text as interpreted by Justice Scalia’s dissent in Babbitt v. Sweet Home Chapter of Communities for a Great Oregon (“Sweet Home”).[1] Under this view, the Services now will not consider habitat modifications that indirectly lead to the death or injury of a population of animals to be prohibited “take,” even if such modification significantly impairs essential behavioral patterns or degrades habitat on which a species depends.[2]
This new interpretation will have a significant impact on how the Services implement the ESA consultation, enforcement, and incidental take permit programs, which in turn will have important potential consequences for regulated entities.
The final rule was published in the Federal Register on July 14, 2026, and will take effect 60 days later, on September 12, 2026.[3]
Background
The ESA prohibits the “take” of endangered and certain threatened species without authorization. The ESA defines “take” to mean “harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct.”[4] (emphasis added). The ESA implementing regulations previously elaborated on the term “harm,” defining it as an act that actually kills or injures wildlife and “may include significant habitat modification or degradation where it actually kills or injures wildlife by significantly impairing essential behavioral patterns, including breeding, feeding, or sheltering.”[5] Thus, the implementing regulation made clear that “harm” included both direct impacts, such as killing or wounding an individual animal, and indirect impacts, such as significant habitat modification or degradation that impairs essential behavioral patterns in a manner that actually kills or injures wildlife.
In 1995, the Supreme Court in Sweet Home rejected a challenge to the Services’ regulation. Citing Chevron U.S.A. Inc. v. NRDC,[6] in a 6-3 decision the Court upheld the Services’ regulatory definition of “harm” to include significant habitat modification as a permissible interpretation of the ESA.[7] Justice Scalia (joined by Chief Justice Rehnquist and Justice Thomas) penned a dissent, arguing via the principle of noscitur a sociis that the surrounding terms — “harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect” — indicate that “harm” should be interpreted consistently with those terms to mean that only direct, affirmative acts against individual animals could constitute a “take.” Therefore, in the dissent’s view, “harm” could not include indirect effects such as habitat modification or degradation that incidentally impair essential behaviors.
Final Rule
On April 17, 2025, the Services proposed to rescind the longstanding regulation defining harm to include significant habitat modification.[8] The Services explained that it was re-visiting the harm regulation in light of the Supreme Court’s 2024 decision in Loper Bright Enterprises v. Raimondo,[9] which overruled the Chevron Doctrine and indicated that courts should interpret statutes according to a single best interpretation. The Services explained their view that the existing regulatory definition did not reflect the single best interpretation of the ESA’s definition of “harm” and therefore should not be maintained.
The Final Rule published on July 14, 2026, finalizes this position and rescinds the prior 1981 rule. With this rescission, the Services’ regulations no longer provide that “harm” includes significant habitat modification or degradation that indirectly kills or injures wildlife by impairing essential behavioral patterns such as breeding, feeding, sheltering, spawning, or migrating. The Services did not promulgate a replacement but instead explained that moving forward they will rely solely on the ESA statutory text as interpreted by Justice Scalia in his Sweet Home dissent. Under this view, “take” encompasses only affirmative conduct intentionally directed at a particular animal or animals. The Services will not view habitat modification that results in indirect and accidental injury to a wildlife population as “take” within the meaning of the Act.
Takeaways
Effects on ESA Implementation
This Final Rule reflects the position of the US government and will guide how the Services address habitat modification in the context of ESA “take” going forward. This will impact the Services’ implementation of the ESA Section 7 consultation, ESA Section 10 Incidental Take Permits (ITPs), and ESA Section 9 enforcement programs.
- Activities with a Federal Nexus
- ESA Section 7 Consultation. Section 7’s requirements that agencies and applicants for federal authorizations and projects with a federal nexus must engage in consultation to ensure that a proposed activity is not likely to jeopardize ESA-listed species or to adversely modify or destroy designated critical habitat should be largely unaffected by the Final Rule. Habitat modification affecting ESA-listed species in most cases will still need to be considered in the jeopardy analysis. Similarly, consultations will still be required to analyze whether the proposed activity will likely result in adverse modification or destruction of designated critical habitat regardless of whether such impacts may or may not have been considered “take.”
- ESA Incidental Take Statements (ITS). The scope of incidental statements could be narrowed under the Final Rule’s interpretation. ESA Section 7 requires the Services in consultation to identify the impact of any incidental take and specify reasonable and prudent measures to minimize such take in the ITS. Compliance with ITS terms and conditions provides a safe harbor for ESA take liability arising from any incidental take. By narrowing the universe of what is considered prohibited under the ESA, the Final Rule may narrow the need for ITS coverage and the imposition of attendant Reasonable and Prudent Measures (RPMs).
- Purely Private Activities
- ESA Section 10 Incidental Take Permits. Incidental take of ESA-listed species caused by purely private activities (i.e., activities with no Federal nexus) require the Services to issue an ITP and accompanying Habitat Conservation Plan (HCP). Under the Final Rule, ITP/HCPs largely will not be required for take attributed solely to habitat modification and the scope of other ITP/HCPs where both direct take and indirect take due to habitat modification will be diminished.
- ESA Section 9 Enforcement. The Services will no longer pursue enforcement for civil or criminal violations of ESA Section 9 solely based on claims of illegal take due to habitat modification.
Effect on Existing and Prior ESA Section 7 Consultations and Section 10 ITPs
The Final Rule explains that the rescission applies only prospectively, stating that “permits or incidental take statements finalized prior to the effective date of this rule will not be required to be reevaluated under this final rule.”[10]
The “Fine Print”
- The Final Rule reflects the Services’ view of the single best interpretation of the ESA and will guide how the Services address habitat modification in the context of ESA “take” going forward. However, it does not conclusively resolve the issue as a matter of law. Following Loper Bright, private parties and NGOs remain free to argue in citizen suits and other litigation that Sweet Home is still binding law notwithstanding the Services’ announced interpretation. Likewise, even if Sweet Home is considered non-binding, following Loper Bright parties remain free to argue in litigation that the now rescinded regulation’s interpretation of harm as encompassing habitat modification represents the single best reading of the statute and must be followed without deference to the Services’ newly announced interpretation. Thus, notwithstanding the Final Rule, regulated entities could still face litigation via citizen suits premised on take due to habitat modification.
- As evidenced by the Sweet Home majority, concurring and dissenting opinions, line-drawing and application of the Scalia dissent’s test to different factual circumstances is not always clear-cut. As the Services work through the variety of factual circumstances that can arise when habitat modification may be in play, a certain level of regulatory uncertainty can be expected.
- The only certainty is that litigation raising facial and as-applied challenges to the Services’ Final Rule and new interpretation is certain. Ultimately, the validity of the Services’ interpretation will likely be determined by the courts.
Because it remains uncertain whether courts will ultimately uphold the Services’ interpretation as the best reading of the ESA, regulated entities should proceed deliberately in evaluating how to respond to the new rule and the resulting uncertainty.
[1] 515 U.S. 687 (1995).
[2] Id. at 720 (Scalia, J., dissenting).
[3] Rescinding the Definition of “Harm” Under the Endangered Species Act, 91 Fed. Reg. 43,300 (July 14, 2026).
[4] 16 U.S.C. Section 1532(19).
[5] 50 CFR Section 17.3.
[6] 467 U.S. 837 (1984).
[7] 515 U.S. 687 (1995).
[8] Rescinding the Definition of “Harm” Under the Endangered Species Act, 90 Fed. Reg. 16,102 (Apr. 17, 2025).
[9] Loper Bright Enterprises v. Raimondo, 603 U.S. 369 (2024).
[10] 91 Fed. Reg. at 43,305 (July 14, 2026).
