OPINION

We must decide whether the Temporary Assistance for Needy Families program, administered by tfie Department of Health and Human Services, qualifies as a program “for the benefit of Indians because of their status as Indians” within the meaning of the Indian Self-Determination and Education Assistance Act.

I

In 1996, Congress passed the Personal Responsibility and Work Opportunity Reconciliation Act (“PRWORA” or the “Act”), which made extensive changes in the welfare laws of this country. The Act replaced the Aid to Families with Dependent Children program (“AFDC”) with a new program of temporary assistance and work requirements, called Temporary Assistance for Needy Families (“TANF”). 42 U.S.C. § 601 , et seq. Under the Act, the federal government provides TANF block grants to interested states, 42 U.S.C. § 603 , or to Indian tribes, 42 U.S.C. § 612 , which then can fund welfare programs for citizens within their jurisdictions, subject to federal conditions.

In October 1997, the Navajo Nation (the “Tribe”) applied to the Secretary of Health and Human Services (“HHS”) to receive TANF funds for citizens within its jurisdiction. However, rather than apply for TANF funds under the provision of PRWORA which allowed Indian tribes to apply directly, 42 U.S.C. § 612 , the Tribe applied for a funded contract under a provision of the Indian Self Determination and Education Assistance Act (“IS-DEAA”), 25 U.S.C. § 450f. Under this provision, the Secretary of Health and Human Services, as well as the Secretary of the Interior, are “directed, upon the request of any Indian tribe ..., to enter into a self-determination contract” with the tribe. 25 U.S.C. § 450f(a)(l).

The ISDEAA defines a “self determination contract” as “a contract ... entered into ... between a tribal organization and the appropriate Secretary for the planning, conduct and administration of programs or services which are otherwise provided to Indian tribes and their members pursuant to Federal law....” 25 U.S.C. § 460b(j). In other words, to the extent that the federal government provides services to members of Indians tribes, or pays others to provide those services, the ISDEAA gives Indian tribes the option of accepting those funds and providing the services “in-house,” as it were.

Not all federal programs, however, are eligible to be transferred to Indian tribes through a self-determination contract; only those programs described in § 450f(a)(l)(A)-(E) are eligible. In this case, the Tribe applied for a self-determination contract under § 450f(a)(l)(E), *868 which includes programs “for the benefit of Indians because of their status as Indians.25 U.S.C. § 450f(a)(l)(E). The Tribe chose to apply for TANF funds under the ISDEAA, rather than under the PRWORA, primarily because it would have received additional funds for administrative costs under the ISDEAA which it would not have received under the PRWORA.

In a November 1997 letter to the Tribe, the Secretary rejected, for two independent reasons, the application because it went “beyond the scope of programs ... covered under [§ 450f(a)(l) ].” 25 U.S.C. § 450f(a)(2)(E). First, the Secretary ruled that because the TANF program served all of the poor, whether Indian or not, the “TANF program is not one that operates for the particular benefit of Indians,” in contravention of § 450f(a)(l)(E). Second, she determined that, even if the TANF program did operate for the particular benefit of Indians, a contract for TANF funds did not meet the requirements of a “self-determination contract” in § 450b(j) because the “TANF program is not a program under which the Federal government would otherwise directly provide services to Indian tribes pursuant to Federal law.”

The Tribe attempted to appeal the Secretary’s decision through administrative procedures, but the Board of Indian Appeals determined that the only remedy available was suit in federal court. As a result, the Tribe filed this suit in February 1998 in United States District Court for the District of Arizona and asked the court to order the Secretary to enter into a self-determination contract with it for TANF funds. The Secretary filed a motion to dismiss for failure to state a claim under Federal Rule of Civil Procedure 12(b)(6), which was granted by the district court on the second ground asserted by the Secretary, that a contract for TANF funds did not meet the requirements of a “self-determination contract,” as defined in § 450b(j). The Tribe filed this timely appeal.

II

Although the district court agreed with the Secretary’s interpretation of the ISDEAA, the district court did not consider whether the Secretary’s interpretation is entitled to substantial deference under Chevron U.S.A., Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837, 842-45 , 104 S.Ct. 2778 , 81 L.Ed.2d 694 (1984). Consequently, we ordered supplemental briefing on this issue. Under Chevron, we employ a two-step process to determine whether we should accord deference to an agency interpretation. First, we ask “whether Congress has directly spoken to the precise question at issue.” Id. at 842 , 104 S.Ct. 2778 . If the meaning of the statute is unambiguous, then “that is the end of the matter....” Id. If, on the other hand, the meaning of the statute is ambiguous, then we ask whether the agency’s interpretation is a reasonable construction of the statute.. Id. at 843 , 104 S.Ct. 2778 .

The Secretary ruled that, because the TANF program “is intended to operate for the benefit of needy families without consideration of the status of these families as Indian or non-Indian,” the TANF program “is not one that operates for the particular benefit of Indians.... ” Thus, the Secretary ruled that the TANF program did not meet the strictures of § 450f(a)(l)(E), that the program which the Tribe seeks to administer was “for the benefit of Indians because of their status as Indians....” 25 U.S.C. § 450f(a)(l)(E). The Tribe argues that the Secretary misconstrued § 450f(a)(l)(E) in making this determination. The Tribe argues that § 450f(a)(l)(E) unambiguously supports the proposition that the TANF program is *869 a one “for the benefit of Indians because of their status as Indians.... ”

The Tribe’s argument in this regard rests exclusively on the fact that, in enacting the PRWORA, Congress separated the provision under which states can apply for a TANF block grant, 42 U.S.C. § 603 , from the provision under which Indian tribes can apply for a TANF block grant, 42 U.S.C. § 612 . The fact that Indians apply for funds under a different provision than do states does not make the TANF program one “for the benefit of Indians because of their status as Indians,” if the funds the Indians receive are otherwise identical to the funds states receive. That is, if the funds are otherwise identical, Indians receive no marginal “benefit” from the separate application provision.

It is not the case, however, that the TANF funds which Indians receive are otherwise identical to those received by states. For example, states receiving TANF block grants are under strict limits regarding the number of years they can allow citizens to receive block grants, 42 U.S.C. § 608 (a)(7), and the portion of citizens receiving block grants who must be employed, 42 U.S.C. § 607 . By contrast, the PRWORA leaves open the possibility that Indian tribes may not be subject to the same constraints on their use of the block grants. 42 U.S.C. § 612 (c)(2) (“The Secretary ... shall establish for each Indian tribe ... minimum work participation requirements [and] appropriate time limits for receipt of welfare-related services ... consistent with the economic conditions and resources available to each tribe....”).

The Secretary interpreted § 450f(a)(l)(E) to require more than preferential treatment for Indians under the program in question. She interpreted “program[] ... for the benefit of Indians because of their status as Indians” to mean that Indians must be the exclusive beneficiaries of the program in question. In her letter, she ruled that the Tribe’s application must be denied because “[t]he TANF program is not one that operates for the particular benefit of Indians.... ” (Emphasis added.) In her brief before this Court, she elaborated on her interpretation by arguing that a program qualifies under § 450f(a)(l)(E) only if “in order to be eligible for the program an individual must be a member of a federally recognized Indian tribe.” (Emphasis added.)

The question under the first step of the Chevron inquiry is whether the phrase “for the benefit of Indians because of their status as Indians” in § 450f(a)(l)(E) has an unambiguous meaning. We conclude that it does not. The plain language of the words “program!] ... for the benefit of Indians because of their status as Indians” is susceptible both to the meaning that the program must be for the exclusive benefit of Indians and the meaning that the program can benefit non-Indians as well as Indians, but that it must benefit Indians on a preferential basis.

Moreover, we find nothing specific in the legislative history of the ISDEAA which sheds any light on which of these two meanings, if either, Congress had in mind when it enacted § 450f(a)(l)(E). Although the legislative history of the act contains multifarious general statements regarding the overall purpose of the ISDEAA, nowhere is the phrase “for the benefit of Indians because of their status as Indians” discussed. Under Chevron step one, such general pronouncements regarding the overall purpose of a complex statute do not constitute conclusive evidence that Congress has “directly spoken” to the meaning of the “precise” statutory phrase in dispute. See Natural Res. Def. Council, Inc. v. EPA, 966 F.2d 1292, 1302 (9th Cir.1992) (“The legislative history is *870 not illuminating. Although it explains that a purpose of the permitting scheme was to attack the most serious sources of discharge first, this general goal is not helpful in discerning the specific meaning of ‘municipal separate storm sewer system serving a population.’ ”); see also Japan Whaling Ass’n v. American Cetacean Soc’y, 478 U.S. 221, 234-35 , 106 S.Ct. 2860 , 92 L.Ed.2d 166 (1986) (holding that, although the legislative history showed that the general purpose of the statute was to punish nations which violated international fishing quotas, this did not establish that the statutory phrase “diminish the effectiveness of an international fishery conservation program” unambiguously meant “violation of international fishing quotas”); Chevron, 467 U.S. at 862 , 104 S.Ct. 2778 (rejecting argument that the legislative history made the statutory language unambiguous because “[t]he general remarks pointed to by respondents were obviously not made with this narrow issue in mind and they cannot be said to demonstrate a Congressional desire” (internal quotation marks omitted)). Thus, we do not find that “Congress has directly spoken to the precise question at issue,” Chevron 467 U.S. at 842-43 , 104 S.Ct. 2778 , and, therefore, we move to the second step in the Chevron inquiry.

With regard to such second step, as we hinted above, we believe that one reasonable interpretation of “programG ... for the benefit of Indians because of their status as Indians” is that Indians must be the exclusive beneficiaries under the program. The language indicates that Indians must benefit under a program in a way that other people do not. As a matter of logic, this could mean either that Indians (1) must be the exclusive beneficiaries of the program, as the Secretary argues, or (2) need only derive some benefit from the program beyond that which other program beneficiaries receive. Thus, the Secretary’s interpretation of the -ISDEAA is one reasonable possibility, and therefore is entitled to deference under Chevron .

Ill

Although we hold that both prongs of Chevron are satisfied in this case, we must confront three arguments that the Secretary’s interpretation is nonetheless not eligible for deference under Chevron .

A

One could argue against the eligibility of Chevron deference in this case as conflicting with the general rule of interpretation of statutes enacted for the benefit of Indian tribes; namely, that such statutes “are to be construed liberally in favor of the Indians, with ambiguous provisions interpreted to their benefit.” Montana v. Blackfeet Tribe of Indians, 471 U.S. 759, 766 , 105 S.Ct. 2399 , 85 L.Ed.2d 753 (1985). That is, even if the meaning of provisions of the ISDEAA are ambiguous, that statute was undoubtedly enacted for the benefit of Indian tribes, and, therefore, instead of deferring to agency interpretations in such circumstances, the court should construe the statute in a way that benefits Indians. Thus, to some extent, the Chevron rule of statutory interpretation and the Blackfeet Tribe rule of statutory interpretation conflict with one another in this case. We have dealt with this conflict by discarding the Blackfeet Tribe rule in favor of the Chevron rule whenever these two general rules of interpretation intersect in the same case. 1 Williams v. *871 Babbitt, 115 F.3d 657 , 663 n. 5 (9th Cir.1997) (“We have therefore held that the liberal construction rule must give way to agency interpretations that deserve Chevron deference .... ”); Seldovia Native Ass’n, Inc. v. Lujan, 904 F.2d 1335, 1342 (9th Cir.1990) (applying Chevron deference instead of canon of statutory construction favoring Indians); Haynes v. United States, 891 F.2d 235, 239 (9th Cir.1989) (declining to apply canons of interpretation favoring Indians “in light of competing deference given to an agency charged with the statute’s administration”). Thus, given that the Secretary’s interpretation of the ISDEAA otherwise meets all of the conditions for Chevron deference, we accord it that deference notwithstanding the fact that the ISDEAA was enacted for the benefit of Indian tribes. 2

B

Another argument against the eligibility of Chevron deference in this case is that the Secretary’s construction of the ISDEAA came in the form of a mere letter denying the Tribe’s application. In Christensen v. Harris County, 529 U.S. 576 , 120 S.Ct. 1655 , 146 L.Ed.2d 621 (2000), the Supreme Court declined to accord Chevron deference to an agency “opinion letter.” Id. at 586-87, 120 S.Ct. 1655 . The Court stated that “[finterpretations such as those in opinion letters — like interpretations contained in policy statements, agency manuals, and enforcement guidelines, all of which lack the force of law — do not warrant Chevron-style deference.” Id. at 587 , 120 S.Ct. 1655 .

Unlike Christensen , however, the Secretary’s letter in this case was not an “opinion letter,” but, rather, a final, albeit informal, adjudication on the merits denying the Tribe’s application for funds. The Supreme Court routinely accords Chevron deference to statutory interpretations performed by agencies in the course of informal adjudications, including an informal adjudication in the form of a letter. E.g., NationsBank of N.C., N.A. v. Variable Annuity Life Ins. Co., 513 U.S. 251, 256-58 , 115 S.Ct. 810 , 130 L.Ed.2d 740 (1995) (according Chevron deference to letter from Comptroller of the Currency granting NationsBank’s application to sell annuities). See also Christensen, 529 U.S. at 590 , 120 S.Ct. 1655 (Scalia, J., concurring in part and concurring in the judgment) (citing cases). Congress delegated to the Secretary the authority to adjudicate in this manner. 25 U.S.C. § 450f(a)(2)(E) (“[T]he Secretary shall, within ninety days after receipt of the proposal, approve the proposal and award the contract unless the Secretary provides written notification to the applicant that contains a specific find *872 ing that clearly demonstrates that ... the program, function, service, or activity ... that is the subject of the proposal is beyond the scope [of programs authorized by Congress].”). Thus, we are bound to accord Chevron deference to the Secretary’s letter given that such deference is otherwise appropriate.

C

Finally, the Tribe argues against the eligibility of Chevron deference in this case because two different agencies, HHS and Interior, administer the ISDEAA. There is nothing in the theory underlying Chevron , however, that disqualifies per se agency interpretations of statutes administered by more than one agency from receiving substantial deference.

1

We are obligated to defer to agency interpretations of statutes because we are obligated to follow Congress’s implicit desire to delegate interpretative authority to the particular agencies‘it selects to administer its statutes. Pauley v. BethEnergy Mines, Inc., 501 U.S. 680, 696 , 111 S.Ct. 2524 , 115 L.Ed.2d 604 (1991) (“When Congress, through express delegation or the introduction of an interpretive gap in the statutory structure, has delegated policy-making authority to an administrative agency, the extent of judicial review of the agency’s policy determinations is limited.”); Adams Fruit Co., Inc. v. Barrett, 494 U.S. 638, 649 , 110 S.Ct. 1384 , 108 L.Ed.2d 585 (1990) (“A precondition to deference under Chevron is a congressional delegation of administrative authority.”). Congress’s implicit desire to delegate interpretative authority to the particular agencies it selects to administer its statutes is not less evident simply because Congress selected more than one particular agency to administer a single statute. Congress very clearly delegated administrative authority over the ISDEAA to both HHS and Interior. The ISDEAA directs “[t]he Secretary ..., upon the request of any Indian tribe ..., to enter into a self-determination contract.... ” 25 U.S.C. § 450f(a)(l). The ISDEAA defines “Secretary” to mean “either the Secretary of Health and Human Services or the Secretary of the Interior or both.” 25 U.S.C. § 450b(i). As a result, there is no reason to disqualify per se interpretations of the ISDEAA by HHS or Interior from receiving Chevron deference. Indeed, in Cook Inlet Native Ass’n v. Bowen, 810 F.2d 1471 (9th Cir.1987), we accorded Chevron deference to HHS’s interpretation of “Indian tribe” in another section of the IS-DEAA, apparently unconcerned that both HHS and Interior administered the IS-DEAA. Id. at 1472-73 (“The construction of the statute by the agency charged with its administration is entitled to substantial deference.”), 1476 (“As discussed above, the legislative history does not indicate that Congress intended to preclude the agency interpretation. The court must, therefore, defer to that interpretation.”).

2

Although there is language in one Supreme Court opinion which arguably suggests that it is inappropriate to accord Chevron deference to agency interpretations of statutes administered by more than one agency, we do not think it controlling here. In Bowen v. American Hospital Ass’n, 476 U.S. 610 , 106 S.Ct. 2101 , 90 L.Ed.2d 584 (1986), the Supreme Court stated, in dicta, id. at 643 , 106 S.Ct. 2101 (“Even according the greatest respect to the Secretary’s action, .... ”), that there was no basis for Chevron deference with regard to an HHS interpretation of section 504 of the Rehabilitation Act of 1973, ostensibly because twenty-six agencies besides HHS also had promulgated regula *873 tions under that statutory provision, id. at 642 n. 30, 106 S.Ct. 2101 . The reason so many other agencies had promulgated regulations under that statutory provision, however, was that § 504 is an anti-discrimination law generally applicable to all federal agencies. 3 In other words, Congress did not delegate authority to administer § 504 to any particular agency or agencies. Therefore, the necessary predicate of Chevron deference — congressional delegation of administrative authority — was missing. 4 This, of course, is much different from the case at hand, where Congress did delegate administrative authority over the ISDEAA to two particular agencies. 5

3

The dissent protests that the distinction between “administrative” and “interpretive” authority is false because (1) “it is the delegation of authority to interpret a statute which triggers Chevron deference,” and (2) “any agency that has been delegated interpretive authority can be said to ‘administer’ the statute.” Dissent at 877 n. 1. With respect, however, we believe that there is a world of difference between a law that delegates authority to one or more organizations to administer it, like the statute involved in this case, and an anti-discrimination law generally applicable to all agencies, like the law in American Hospital.

In the former case, Congress has said: here is the general outline of what we command, and we give you the authority to develop policy and to fill in the details. An agency thus has freedom to develop policy in implementing the outline, subject only to staying within Congress’s grant of *874 authority. In the latter case, however, Congress itself has developed policy and mandated compliance. The agency (or agencies) subject to such a command have only to interpret the congressional mandate and to apply it. See United States v. Mead Corp., 533 U.S. 218, 227 , 121 S.Ct. 2164, 2171 , 150 L.Ed.2d 292 (2001) (“[WJhether or not they enjoy any express delegation of authority on a particular question, agencies charged with applying a statute necessarily make all sorts of interpretive choices_”). It makes eminent sense that an agency in the former position has a far superior claim to deference than an agency in the latter: an agency that has freedom to develop policy in its interpretation of a congressionally-delegat-ed statutory scheme should be entitled to far more leeway than one merely told to comply with policy formulated by Congress itself. See FDA v. Brown & Williamson Tobacco Corp., 529 U.S. 120 , 120 5.Ct. 1291, 146 L.Ed.2d 121 (2000) (“Deference under Chevron to an agency’s construction of a statute that it administers is premised on the theory that a statute’s ambiguity constitutes an implicit delegation from Congress to the agency to fill in the statutory gaps.”); Chevron, 467 U.S. at 843 , 104 S.Ct. 2778 (“ ‘The power of an administrative agency to administer a con-gressionally created ... program necessarily requires the formulation of policy and the making of rules to fill any gap left, implicitly or explicitly, by Congress.’ ” (quoting Morton v. Ruiz, 415 U.S. 199, 231, 94 S.Ct. 1055 , 39 L.Ed.2d 270 (1974))).

Thus, even if the language from American Hospital is not dicta — which we believe it is — the distinction between the statute at issue in that case and the statute here sufficiently explains why we reach a different result than the American Hospital Court. We therefore do not read American Hospital to bar us from applying Chevron deference in this case. 6

4

We are mindful of the fact that when more than one agency interprets a statute, such agencies might, at some point, reasonably interpret the statute in different and conflicting manners. 7 Al *875 though we do not confront such a situation in this case, we do not believe that the theoretical possibility of such a situation is sufficient grounds to jettison Chevron deference in the many situations where only one of the agencies has weighed in on a particular question of statutory interpretation, which is the Ciase here, or where all of the agencies weigh in on a question in the same way, which was the case in Cook Inlet, 810 F.2d at 1474 . In those circumstances where agencies do offer conflicting interpretations, we would be forced to employ some form of de novo review, either to choose the most reasonable of the reasonable interpretations offered by the agencies or to fashion our own interpretation of the statute. See Commonwealth Edison Co. v. Vega, 174 F.3d 870, 875 (7th Cir.1999) (“A final complication is that the administration of ERISA is shared between the Labor Department and the Treasury Department.... [But] there is no conflict between the two agencies and therefore no need to decide which should have the whip hand.”).

5

We therefore conclude that, in addition to satisfying both prongs of Chevron , the Secretary’s interpretation of the ISDEAA is eligible for deference under Chevron . As a result, we hold that the Secretary was not obligated to approve the Tribe’s self-determination contract for TANF funds. 8

IV

For the foregoing reasons, the district court’s judgment for the Secretary is

AFFIRMED.

. We recognize that two Circuits disagree with our rule deferring to agency interpretations of statutes enacted for the benefit of Indians. Ramah Navajo Chapter v. Lujan, 112 F.3d 1455, 1461-62 (10th Cir.1997) (rejecting Ninth Circuit approach); Albuquerque Indian *871 Rights v. Lujan, 930 F.2d 49, 58-59 (D.C.Cir.1991) (same).

. The dissent decries the fact that under our precedents, where Chevron encounters a conflict with Blackfeet Tribe, Chevron controls. See Dissent at 875 ("We are the only circuit to hold that in the event of a conflict between the principles of administrative agency deference under [Chevron ] ... and deference to Native American interests under [Blackfeet Tribe'] ..., the latter must give way.... No other circuit has since followed our lead, while two other have expressly gone the other way.”) (citations omitted), 880 (“Instead of Chevron deference, ... I believe the appropriate interpretive principle to apply here is that of construing statutory ambiguities in favor of Native American interests under Blackfeet Tribe.”). Whatever the merits of the dissent’s view — it presents no compelling argument that our precedents are wrong, but merely points out that other circuits do not agree with them — our cases compel this recognition, and we respectfully decline the dissent’s invitation to flout our court's prior decisions. See United States v. Camper, 66 F.3d 229, 232 (9th Cir.1995) (”[O]nly a panel sitting en banc may overturn existing Ninth Circuit precedent.”).

. Section 504 of the Rehabilitation Act of 1973 reads:

29 U.S.C. § 794 .

. This observation also explains language similar to American Hospital found in a line of cases from the D.C. Circuit. For example, in Proffitt v. FDIC, 200 F.3d 855 (D.C.Cir.2000), the court stated that "[w]hen a statute is administered by more than one agency, a particular agency’s interpretation is not entitled to Chevron deference.” Id. at 860 , 104 S.Ct. 2778 . The context in which this statement was uttered, however, was much like the context in American Hospital. The question in Proffitt was whether Chevron deference should be accorded to the FDIC’s interpretation of the word "penalty” in 28 U.S.C. § 2462 . Id. This statute reads:

28 U.S.C. § 2462 . Congress did not delegate administrative authority to any particular agency to administer this statute; it is a generally applicable statute of limitations by which all agencies must abide. Thus, as in American Hospital, the predicate decision by Congress to delegate administrative authority to a particular agency was lacking.

. The dissent criticizes our reading of Proffitt , and argues that in Scales v. INS, 232 F.3d 1159 (9th Cir.2000) we cited the D.C. Circuit's decision in Proffitt as support for refusing to accord Chevron deference to the U.S. State Department's definition of the requirements for American citizenship. See Scales, 232 F.3d at 1165 ("When a statute is administered by more than one agency, a particular agency's interpretation is not entitled to Chevron deference." (citing Proffitt, 200 F.3d at 860 )). Au contraire! In Scales it was clear that "[d]etermination of Petitioner's citizenship is not a duty of the State Department-... but of the Attorney General,” id.; thus, Scales simply did not involve the two-agency problem that is presented in this case.

. Moreover, the Court in American Hospital noted that Chevron deference was inappropriate in that case because it was unlikely that the twenty-seven agencies which promulgated regulations under § 504 had any expertise relative to the courts in interpreting language that generally prohibited discrimination. American Hospital, 476 U.S. at 642 n. 30, 106 S.Ct. 2101 . By contrast, there can be little doubt that the two agencies to whom Congress delegated administrative authority over the ISDEAA, both of which oversee many programs involving Indians, have expertise relative to the courts in determining which of their programs meet the statutory requirements for a self-determination contract.

. The dissent suggests that Chevron deference when more than one agency is involved is impractical for two reasons. First, it argues that some sort of line must be drawn with regard to the number of agencies to whom Congress can delegate administrative authority without disrupting Chevron deference to any or all of them. Second, the dissent seems to contend that Chevron deference in the multiple-agency context will create an undesirable race between agencies to interpret statutes and to have those interpretations approved by a court. With respect, it seems that the dissent's fears are misplaced.

As to the dissent's first concern, while it is perhaps possible in theory that Congress might delegate administrative authority over the same statute to an unwieldy number of agencies, Congress has every reason not to do so because it would not want to disrupt the administration of its own statutes. And even if Congress did engage in the kind of mass delegation the dissent fears, once any two of the delegee agencies disagreed over an interpretation of the statute, the courts would likely be called upon to select the proper interpretation of the statute.

The dissent’s second concern also seems overwrought, given that a first interpreta *875 tion — even if approved by a court — does not create an immutable rule. Even if a court approves an agency's interpretation of an ambiguous statute, it does not establish that such an interpretation is the interpretation of the statute. It merely establishes that such an interpretation is one of many reasonable interpretations of the statute. Indeed, Chevron allows an agency to change its interpretation of an ambiguous statute at any time and obligates courts to defer to the new interpretation — no matter how different it is from the old interpretation. See Rust v. Sullivan, 500 U.S. 173, 186 , 111 S.Ct. 1759 , 114 L.Ed.2d 233 (1991) ("This Court has rejected the argument that an agency's interpretation is not entitled to deference because it represents a sharp break with prior interpretations of the statute in question.” (internal quotation marks omitted)). And as for the dissent's concern that "as a practical matter, the first-mover would likely wield considerable advantages that would make a court reluctant to reverse course upon subsequent review; for example, any subsequent actor might be required to justify deviation from the original rule,” Dissent at 880, we can only observe in bewildered bemusement that the dissent cites no statute or precedent that would require such a justification.

. Because we agree with the first ground articulated by the Secretary in denying the Tribe’s application, we need not consider the second ground, which was the ground relied upon by the district court.