Barrett, J., concurring
its wheelhouse. For instance, in Gonzales v. Oregon, we rebuffed an interpretive rule from the Attorney General that restricted the use of controlled substances in physician-assisted suicide. 546 U. S., at 254, 275. This judgment, we explained, was a medical one that lay beyond the Attorney General’s expertise, and so a sturdier source of statutory authority than “an implicit delegation” was required. Id., at 267–268. Likewise, in King v. Burwell, we blocked the Internal Revenue Service’s (IRS’s) attempt to decide whether the Affordable Care Act’s tax credits could be available on federally established exchanges. 576 U. S., at 485–486. Among other things, the IRS’s lack of “expertise in crafting health insurance policy” made us think that “had Congress wished to assign that question to an agency, it surely would have done so expressly.” Id., at 486. Echoing the theme, our reasoning in Alabama Association of Realtors rested partly on the fact that the CDC’s eviction moratorium “intrude[d] into … the landlord-tenant relationship”—hardly the day-in, day-out work of a public-health agency. 594 U. S., at ___ (slip op., at 6). National Federation of Independent Business v. OSHA is of a piece. 595 U. S. ___ (2022) (per curiam). There, we held that the Occupational Safety and Health Administration’s (OSHA’s) authority to ensure “ ‘safe and healthful working conditions’ ” did not encompass the power to mandate the vaccination of employees; as we explained, the statute empowered the agency “to set workplace safety standards, not broad public health measures.” Id., at ___, ___ (slip op., at 2, 6). The shared intuition behind these cases is that a reasonable speaker would not understand Congress to confer an unusual form of authority without saying more.
We have also pumped the brakes when “an agency claims to discover in a long-extant statute an unheralded power to regulate ‘a significant portion of the American economy.’ ” Utility Air, 573 U. S., at 324. Of course, an agency’s post-
