In our prior coverage of Kisor v. Wilkie, we predicted that the Court would impose “greater scrutiny” on “administrative agencies’ . . . interpretation of their regulations.”  And the Court did.  The Court’s decision will affect every aspect of the federal government’s regulation of environmental, safety, and health.

At the end of its term, the US Supreme Court issued its opinion in Kisor v. Wilkie—upholding but limiting Auer deference.  Auer instructs that courts must defer to an agency’s construction of its own regulation unless that interpretation is “plainly erroneous or inconsistent with the regulation.”  (Indeed, under Auer (before Kisor), the US Supreme Court upheld regulations even when the interpretation was not “the best one.”) Auer deference, however, will work much differently going forward.