Document ID: ./input/supremecourt_opinions/opinions/23pdf/22-451_7m58.pdf
Page Number: 35

Cite as:  603 U. S. ____ (2024) 

27 

Opinion of the Court 

J.,  dissenting  from  denial  of  certiorari)  (slip  op.,  at  11); 
Cuozzo, 579 U. S., at 286 (THOMAS, J., concurring); Scalia, 
1989  Duke  L. J.,  at  517;  see  also  post,  at  15  (opinion  of 
KAGAN, J.).  So we have spent the better part of four decades 
imposing one limitation on Chevron after another, pruning 
its presumption on the understanding that “where it is in
doubt that Congress actually intended to delegate particu-
lar interpretive authority to an agency, Chevron is ‘inappli-
cable.’ ”    United  States  v.  Mead  Corp.,  533  U. S.  218,  230 
(2001) (quoting Christensen v. Harris County, 529 U. S. 576, 
597  (2000)  (Breyer,  J.,  dissenting));  see  also  Adams  Fruit 
Co. v. Barrett, 494 U. S. 638, 649 (1990). 

Consider the many refinements we have made in an ef-
fort  to  match  Chevron’s  presumption  to  reality.  We  have 
said that Chevron applies only “when it appears that Con-
gress delegated authority to the agency generally to make 
rules carrying the force of law, and that the agency inter-
pretation claiming deference was promulgated in the exer-
cise  of  that  authority.”  Mead,  533  U. S.,  at  226–227.    In 
practice,  that  threshold  requirement—sometimes  called 
Chevron “step zero”—largely limits Chevron to “the fruits of 
notice-and-comment  rulemaking  or  formal  adjudication.” 
533 U. S., at 230.  But even when those processes are used, 
deference  is  still  not  warranted  “where  the  regulation  is
‘procedurally defective’—that is, where the agency errs by
failing to follow the correct procedures in issuing the regu-
lation.”  Encino Motorcars, LLC v. Navarro, 579 U. S. 211, 
220 (2016) (quoting Mead, 533 U. S., at 227).

Even  where  those  procedural  hurdles  are  cleared,  sub-
stantive ones remain.  Most notably, Chevron does not ap-
ply  if  the  question  at  issue  is  one  of  “deep  ‘economic  and
political significance.’ ”  King v. Burwell, 576 U. S. 473, 486 
(2015).  We  have  instead  expected  Congress  to  delegate
such  authority  “expressly”  if  at  all,  ibid.,  for  “[e]xtraordi-
nary grants of regulatory authority are rarely accomplished 
through ‘modest words,’ ‘vague terms,’ or ‘subtle device[s],’ ”