concurring:
I write separately to express my view that the Court need not reach the second step of Chevron for a more fundamental reason; namely, that the ADA contains no ambiguity that could trigger that analysis. DOT proposes as the statute’s deference-triggering ambiguity the fact that the statute does not expressly state that the remedies detailed in § 12188 are to be “exclusive.” In essence, the agency’s position — and the District Court’s holding— is that the absence of a statutory grant of power is itself an ambiguity that calls for Chevron deference. See, e.g., Mem. Op. at 28 (“The plain language [of the ADA] indicates that Congress did not explicitly forbid the Secretary from including a compensation mechanism in the OTRB accessibility regulations.”); Appellee’s brief at 43 (proposing that the “first step of the Chevron analysis ... can be resolved quickly here” because Congress “neither required nor prohibited the Secretary from promulgating a compensation provision” and because “Congress did not place any specific limitations on the contents of the OTRB rules”). An agency, DOT submits, is free to impose any otherwise-reasonable rule that Congress has not expressly prohibited.
I would conclude that the second step of Chevron is not even implicated in this case. Chevron step two applies only when a statute contains an ambiguity. But Congress’s failure to grant an agency a given power is not an ambiguity as to whether that power has, in fact, been granted. On the contrary, and as this Court persistent-' ly has recognized, a statutory silence on the granting of a power is a denial of that power to the agency. See, e.g., Backcountry Against Dumps v. EPA 100 F.3d 147, 150 (D.C.Cir.1996) (rejecting EPA’s argument “that, since section 6945(c) is silent as to its application to Indian tribes, the statute is ‘ambiguous’ ”); Ethyl Corp. v. EPA 51 F.3d 1053, 1060 (D.C.Cir.1995) (“We refuse, once again, to presume a delegation of power merely because Congress has not expressly withheld such power.”); see also Adams Fruit Co. v. Barrett, 494 U.S. 638, 649, 110 S.Ct. 1384, 108 L.Ed.2d 585 (1990) (“A ‘gap’ is not created in a statutory scheme merely because a statute does not restate the truism that States may not pre-empt federal law.”).
This Court, while sitting en banc, has already disposed of DOT’s argument that the judiciary must afford Chevron deference to an agency’s interpretation of a statutory silence. “To suggest,” we reasoned,
that Chevron step two is implicated any time a statute does not expressly negate the existence of a claimed administrative power (i.e. when the statute is not written in “thou shalt not” terms), is both flatly unfaithful to the principles of administrative law outlined above, and refuted by precedent.... Were courts to presume a delegation of power absent an express withholding of such power, agencies would enjoy virtually limitless hegemony, a result plainly out of keeping with Chevron and quite likely with the Constitution as well.
Railway Labor Executives’ Ass’n v. National Mediation Bd., 29 F.3d 655, 671 (D.C.Cir.1994) (en banc) (emphasis in orig*9inal) (citations omitted). The ANA is not ambiguous on whether it grants DOT the power to authorize money damages against non-complying bus companies. The statute simply does not grant it that power.
The proposition that statutory silences are not Chevron-triggering ambiguities follows from the very nature of administrative agencies. Agencies have no inherent powers. They instead are creatures of statute, and may act only because, and only to the extent that, Congress affirmatively has delegated them the power to act. See Louisiana Pub. Serv. Comm’n v. FCC, 476 U.S. 355, 374, 106 S.Ct. 1890, 90 L.Ed.2d 369 (1986) (“[A]n agency literally has no power to act ... unless and until Congress confers power upon it.”); Rail-tvay Labor Executives’ Ass’n, 29 F.3d at 670 (“Agencies owe their capacity to act to the delegation of authority, either express or implied, from the legislature.”).
Hence if Congress wishes to deny an agency a given power, it need not expressly restrict the agency; it is enough for Congress simply to decline to delegate power. In the same way, a statute that is completely silent on the question of whether it confers a power does not vest the agency with the discretion to determine the scope of that power. See Natural Resources Defense Council v. Reilly, 983 F.2d 259, 266 (D.C.Cir.1993) (“ ‘[I]t is only legislative intent to delegate such authority that entitles an agency to advance its own statutory construction for review under the deferential second prong of Chevron.’ ” (quoting Kansas City v. Dep’t of Housing & Urban Dev., 923 F.2d 188, 191—92 (D.C.Cir.1991))). In order for there to be an ambiguous grant of power, there must be a grant of power in the first instance. There is none here.
Moreover, accepting DOT’S contention— that a statutory silence empowers it to promulgate any rules that Congress has not expressly forbidden — would vest agencies with near-plenary authority. Agencies would become the nation’s principal lawmakers. After all, it is the norm for statutes to be silent on whether they grant various powers to agencies. The ADA is silent on whether DOT has the power to oblige bus companies to give disabled persons free passage. It is also silent on whether DOT has the power to require that bus companies transport disabled passengers in their own individual buses. If we were to accept DOT’S view, we would be obliged to conclude that Congress somehow, if only ambiguously, has authorized the agency to adopt both of those rules, and consequently would be bound to afford them Chevron deference. We would not, of course, be obliged to rubber-stamp an agency’s interpretation of those, or any other, statutory silences; any such interpretation would still have to satisfy the reasonableness test of Chevron step two. See Chevron, 467 U.S. at 844, 104 S.Ct. 2778 (requiring courts to uphold only “a reasonable interpretation made by the administrator of an agency”). But it makes a mockery of Chevron to suggest that its second prong is even implicated by Congress’s failure to deny a power to an agency.
The agency’s position — that that which is not forbidden is permitted — turns the basic assumption of the American system of government on its head. Our Constitution permits the national government to exercise only those powers affirmatively granted to it by the people of the several states. See, e.g., U.S. Const. amend. X; McCulloch v. Maryland, 17 U.S. (4 Wheat.) 316, 405, 4 L.Ed. 579 (1819) (“This government is acknowledged by all to be one of enumerated powers”); Marbury v. Madison, 5 U.S. (1 Cranch) 137, 176, 2 L.Ed. 60 (1803) (“The powers of the legislature are defined and limited; and that those limits may not be mistaken or forgotten, the constitution is written.”). The Constitution’s presumption is that a power not expressly conferred on the federal government has been denied to it. The same principle informs Congress’s delegations of power to administrative agencies. Unless Congress delegates authority to an agency, *10the agency is without power to act. And, it goes without saying, courts need not defer to an agency’s interpretation, reasonable or otherwise, of a non-existent grant of power.