North Carolina Bd. of Dental Examiners v. FTC, 574 U.S. 494 (2015)

NOTICE: This opinion is subject to formal revision before publication in the preliminary print of the United States Reports. Readers are requested to notify the Reporter of Decisions, Supreme Court of the United States, Washington, D. C. 20543, of any typographical or other formal errors, in order that corrections may be made before the preliminary print goes to press.

SUPREME COURT OF THE UNITED STATES

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No. 13–534

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NORTH CAROLINA STATE BOARD OF DENTAL EXAMINERS, PETITIONER v. FEDERAL TRADE COMMISSION

on writ of certiorari to the united states court of appeals for the fourth circuit

[February 25, 2015]

Justice Kennedy delivered the opinion of the Court.

This case arises from an antitrust challenge to the actions of a state regulatory board. A majority of the board’s members are engaged in the active practice of the profession it regulates. The question is whether the board’s actions are protected from Sherman Act regulation under the doctrine of state-action antitrust immunity, as defined and applied in this Court’s decisions beginning with Parker v. Brown,317 U. S. 341 (1943).

I

A

In its Dental Practice Act (Act), North Carolina has declared the practice of dentistry to be a matter of public concern requiring regulation. N. C. Gen. Stat. Ann. §90–22(a) (2013). Under the Act, the North Carolina State Board of Dental Examiners (Board) is “the agency of the State for the regulation of the practice of dentistry.” §90–22(b).

The Board’s principal duty is to create, administer, and enforce a licensing system for dentists. See §§90–29 to 90–41. To perform that function it has broad authority over licensees. See §90–41. The Board’s authority with respect to unlicensed persons, however, is more restricted: like “any resident citizen,” the Board may file suit to “perpetually enjoin any person from . . . unlawfully practicing dentistry.” §90–40.1.

The Act provides that six of the Board’s eight members must be licensed dentists engaged in the active practice of dentistry. §90–22. They are elected by other licensed dentists in North Carolina, who cast their ballots in elections conducted by the Board. Ibid. The seventh member must be a licensed and practicing dental hygienist, and he or she is elected by other licensed hygienists. Ibid. The final member is referred to by the Act as a “consumer” and is appointed by the Governor. Ibid. All members serve 3-year terms, and no person may serve more than two consecutive terms. Ibid. The Act does not create any mechanism for the removal of an elected member of the Board by a public official. See ibid.

Board members swear an oath of office, §138A–22(a), and the Board must comply with the State’s Administrative Procedure Act, §150B–1 et seq., Public Records Act, §132–1 et seq., and open-meetings law, §143–318.9 et seq. The Board may promulgate rules and regulations governing the practice of dentistry within the State, provided those mandates are not inconsistent with the Act and are approved by the North Carolina Rules Review Commission, whose members are appointed by the state legislature. See §§90–48, 143B–30.1, 150B–21.9(a).

B

In the 1990’s, dentists in North Carolina started whitening teeth. Many of those who did so, including 8 of the Board’s 10 members during the period at issue in this case, earned substantial fees for that service. By 2003, nondentists arrived on the scene. They charged lower prices for their services than the dentists did. Dentists soon began to complain to the Board about their new competitors. Few complaints warned of possible harm to consumers. Most expressed a principal concern with the low prices charged by nondentists.

Responding to these filings, the Board opened an investigation into nondentist teeth whitening. A dentist member was placed in charge of the inquiry. Neither the Board’s hygienist member nor its consumer member participated in this undertaking. The Board’s chief operations officer remarked that the Board was “going forth to do battle” with nondentists. App. to Pet. for Cert. 103a. The Board’s concern did not result in a formal rule or regulation reviewable by the independent Rules Review Commission, even though the Act does not, by its terms, specify that teeth whitening is “the practice of dentistry.”

Starting in 2006, the Board issued at least 47 cease-and-desist letters on its official letterhead to nondentist teeth whitening service providers and product manufacturers. Many of those letters directed the recipient to cease “all activity constituting the practice of dentistry”; warned that the unlicensed practice of dentistry is a crime; and strongly implied (or expressly stated) that teeth whitening constitutes “the practice of dentistry.” App. 13, 15. In early 2007, the Board persuaded the North Carolina Board of Cosmetic Art Examiners to warn cosmetologists against providing teeth whitening services. Later that year, the Board sent letters to mall operators, stating that kiosk teeth whiteners were violating the Dental Practice Act and advising that the malls consider expelling violators from their premises.

These actions had the intended result. Nondentists ceased offering teeth whitening services in North Carolina.

C

In 2010, the Federal Trade Commission (FTC) filed an administrative complaint charging the Board with violating §5 of the Federal Trade Commission Act,38Stat.719, as amended,15 U. S. C. §45. The FTC alleged that the Board’s concerted action to exclude nondentists from the market for teeth whitening services in North Carolina constituted an anticompetitive and unfair method of competition. The Board moved to dismiss, alleging state-action immunity. An Administrative Law Judge (ALJ) denied the motion. On appeal, the FTC sustained the ALJ’s ruling. It reasoned that, even assuming the Board had acted pursuant to a clearly articulated state policy to displace competition, the Board is a “public/private hybrid” that must be actively supervised by the State to claim immunity. App. to Pet. for Cert. 49a. The FTC further concluded the Board could not make that showing.

Following other proceedings not relevant here, the ALJ conducted a hearing on the merits and determined the Board had unreasonably restrained trade in violation of antitrust law. On appeal, the FTC again sustained the ALJ. The FTC rejected the Board’s public safety justification, noting, inter alia, “a wealth of evidence . . . suggesting that non-dentist provided teeth whitening is a safe cosmetic procedure.” Id., at 123a.

The FTC ordered the Board to stop sending the cease-and-desist letters or other communications that stated nondentists may not offer teeth whitening services and products. It further ordered the Board to issue notices to all earlier recipients of the Board’s cease-and-desist orders advising them of the Board’s proper sphere of authority and saying, among other options, that the notice recipients had a right to seek declaratory rulings in state court.

On petition for review, the Court of Appeals for the Fourth Circuit affirmed the FTC in all respects. 717 F. 3d 359, 370 (2013). This Court granted certiorari. 571 U. S. ___ (2014).

II

Federal antitrust law is a central safeguard for the Nation’s free market structures. In this regard it is “as important to the preservation of economic freedom and our free-enterprise system as the Bill of Rights is to the protection of our fundamental personal freedoms.” United States v. Topco Associates, Inc.,405 U. S. 596,610 (1972). The antitrust laws declare a considered and decisive prohibition by the Federal Government of cartels, price fixing, and other combinations or practices that undermine the free market.

The Sherman Act,26Stat.209, as amended,15 U. S. C. §1 et seq., serves to promote robust competition, which in turn empowers the States and provides their citizens with opportunities to pursue their own and the public’s welfare. See FTC v. Ticor Title Ins. Co.,504 U. S. 621,632 (1992). The States, however, when acting in their respective realm, need not adhere in all contexts to a model of unfettered competition. While “the States regulate their economies in many ways not inconsistent with the antitrust laws,” id., at 635–636, in some spheres they impose restrictions on occupations, confer exclusive or shared rights to dominate a market, or otherwise limit competition to achieve public objectives. If every duly enacted state law or policy were required to conform to the mandates of the Sherman Act, thus promoting competition at the expense of other values a State may deem fundamental, federal antitrust law would impose an impermissible burden on the States’ power to regulate. See Exxon Corp. v. Governor of Maryland,437 U. S. 117,133 (1978); see also Easterbrook, Antitrust and the Economics of Federalism, 26 J. Law & Econ. 23, 24 (1983).

For these reasons, the Court in Parker v. Brown interpreted the antitrust laws to confer immunity on anticompetitive conduct by the States when acting in their sovereign capacity. See 317 U. S., at 350–351. That ruling recognized Congress’ purpose to respect the federal balance and to “embody in the Sherman Act the federalism principle that the States possess a significant measure of sovereignty under our Constitution.” Community Communications Co. v. Boulder,455 U. S. 40,53 (1982). Since 1943, the Court has reaffirmed the importance of Parker’s central holding. See, e.g., Ticor, supra, at 632–637; Hoover v. Ronwin,466 U. S. 558,568 (1984); Lafayette v. Louisiana Power & Light Co.,435 U. S. 389–400 (1978).

III

In this case the Board argues its members were invested by North Carolina with the power of the State and that, as a result, the Board’s actions are cloaked with Parker immunity. This argument fails, however. A nonsovereign actor controlled by active market participants—such as the Board—enjoys Parker immunity only if it satisfies two requirements: “first that ‘the challenged restraint . . . be one clearly articulated and affirmatively expressed as state policy,’ and second that ‘the policy . . . be actively supervised by the State.’ ” FTC v. Phoebe Putney Health System, Inc., 568 U. S. ___, ___ (2013) (slip op., at 7) (quoting California Retail Liquor Dealers Assn. v. Midcal Aluminum, Inc., 445 U. S. 97,105 (1980)). The parties have assumed that the clear articulation requirement is satisfied, and we do the same. While North Carolina prohibits the unauthorized practice of dentistry, however, its Act is silent on whether that broad prohibition covers teeth whitening. Here, the Board did not receive active super-vision by the State when it interpreted the Act as ad-dressing teeth whitening and when it enforced that policy by issuing cease-and-desist letters to nondentist teeth whiteners.

A

Although state-action immunity exists to avoid conflicts between state sovereignty and the Nation’s commitment to a policy of robust competition, Parker immunity is not unbounded. “[G]iven the fundamental national values of free enterprise and economic competition that are embodied in the federal antitrust laws, ‘state action immunity is disfavored, much as are repeals by implication.’ ” Phoebe Putney, supra, at ___ (slip op., at 7) (quoting Ticor, supra, at 636).

An entity may not invoke Parker immunity unless the actions in question are an exercise of the State’s sovereign power. See Columbia v. Omni Outdoor Advertising, Inc.,499 U. S. 365,374 (1991). State legislation and “decision[s] of a state supreme court, acting legislatively rather than judicially,” will satisfy this standard, and “ipso facto are exempt from the operation of the antitrust laws” because they are an undoubted exercise of state sovereign authority. Hoover, supra, at 567–568.

But while the Sherman Act confers immunity on the States’ own anticompetitive policies out of respect for federalism, it does not always confer immunity where, as here, a State delegates control over a market to a non-sovereign actor. See Parker, supra, at 351 (“[A] state does not give immunity to those who violate the Sherman Act by authorizing them to violate it, or by declaring that their action is lawful”). For purposes of Parker, a nonsovereign actor is one whose conduct does not automatically qualify as that of the sovereign State itself. See Hoover, supra, at 567–568. State agencies are not simply by their governmental character sovereign actors for purposes of state-action immunity. See Goldfarb v. Virginia State Bar,421 U. S. 773,791 (1975) (“The fact that the State Bar is a state agency for some limited purposes does not create an antitrust shield that allows it to foster anticompetitive practices for the benefit of its members”). Immunity for state agencies, therefore, requires more than a mere facade of state involvement, for it is necessary in light of Parker’s rationale to ensure the States accept political accountability for anticompetitive conduct they permit and control. See Ticor, 504 U. S., at 636.

Limits on state-action immunity are most essential when the State seeks to delegate its regulatory power to active market participants, for established ethical standards may blend with private anticompetitive motives in a way difficult even for market participants to discern. Dual allegiances are not always apparent to an actor. In consequence, active market participants cannot be allowed to regulate their own markets free from antitrust account-ability. See Midcal, supra, at 106 (“The national policy in favor of competition cannot be thwarted by casting [a] gauzy cloak of state involvement over what is essentially a private price-fixing arrangement”). Indeed, prohibitions against anticompetitive self-regulation by active market participants are an axiom of federal antitrust policy. See, e.g., Allied Tube & Conduit Corp. v. Indian Head, Inc.,486 U. S. 492,501 (1988); Hoover, supra, at 584 (Stevens, J., dissenting) (“The risk that private regulation of market entry, prices, or output may be designed to confer monop-oly profits on members of an industry at the expense of the consuming public has been the central concern of . . . our antitrust jurisprudence”); see also Elhauge, The Scope of Antitrust Process, 104 Harv. L. Rev. 667, 672 (1991). So it follows that, under Parker and the Supremacy Clause, the States’ greater power to attain an end does not include the lesser power to negate the congressional judgment embodied in the Sherman Act through unsupervised delegations to active market participants. See Garland, Antitrust and State Action: Economic Efficiency and the Political Process, 96 Yale L. J. 486, 500 (1986).

Parker immunity requires that the anticompetitive conduct of nonsovereign actors, especially those authorized by the State to regulate their own profession, result from procedures that suffice to make it the State’s own. See Goldfarb, supra, at 790; see also 1A P. Areeda & H. Hovencamp, Antitrust Law ¶226, p. 180 (4th ed. 2013) (Areeda & Hovencamp). The question is not whether the challenged conduct is efficient, well-functioning, or wise. See Ticor, supra, at 634–635. Rather, it is “whether anticompetitive conduct engaged in by [nonsovereign actors] should be deemed state action and thus shielded from the antitrust laws.” Patrick v. Burget,486 U. S. 94,100 (1988).

To answer this question, the Court applies the two-part test set forth in California Retail Liquor Dealers Assn. v. Midcal Aluminum, Inc.,445 U. S. 97, a case arising from California’s delegation of price-fixing authority to wine merchants. Under Midcal, “[a] state law or regulatory scheme cannot be the basis for antitrust immunity unless, first, the State has articulated a clear policy to allow the anticompetitive conduct, and second, the State provides active supervision of [the] anticompetitive conduct.” Ticor, supra, at 631 (citing Midcal, supra, at 105).

Midcal’s clear articulation requirement is satisfied “where the displacement of competition [is] the inherent, logical, or ordinary result of the exercise of authority delegated by the state legislature. In that scenario, the State must have foreseen and implicitly endorsed the anticompetitive effects as consistent with its policy goals.” Phoebe Putney, 568 U. S., at ___ (slip op., at 11). The active supervision requirement demands, inter alia, “that state officials have and exercise power to review particular anticompetitive acts of private parties and disapprove those that fail to accord with state policy.” Patrick, supra, U. S., at 101.

The two requirements set forth in Midcal provide a proper analytical framework to resolve the ultimate question whether an anticompetitive policy is indeed the policy of a State. The first requirement—clear articulation—rarely will achieve that goal by itself, for a policy may satisfy this test yet still be defined at so high a level of generality as to leave open critical questions about how and to what extent the market should be regulated. See Ticor, supra, at 636–637. Entities purporting to act under state authority might diverge from the State’s considered definition of the public good. The resulting asymmetry between a state policy and its implementation can invite private self-dealing. The second Midcal requirement—active supervision—seeks to avoid this harm by requiring the State to review and approve interstitial policies made by the entity claiming immunity.

Midcal’s supervision rule “stems from the recognition that ‘[w]here a private party is engaging in anticompetitive activity, there is a real danger that he is acting to further his own interests, rather than the governmental interests of the State.’ ” Patrick, supra, at 100. Concern about the private incentives of active market participants animates Midcal’s supervision mandate, which demands “realistic assurance that a private party’s anticompetitive conduct promotes state policy, rather than merely the party’s individual interests.” Patrick, supra, at 101.

B

In determining whether anticompetitive policies and conduct are indeed the action of a State in its sovereign capacity, there are instances in which an actor can be excused from Midcal’s active supervision requirement. In Hallie v. Eau Claire, 471 U. S. 34, 45 (1985), the Court held municipalities are subject exclusively to Midcal’s “ ‘clear articulation’ ” requirement. That rule, the Court observed, is consistent with the objective of ensuring that the policy at issue be one enacted by the State itself. Hallie explained that “[w]here the actor is a municipality, there is little or no danger that it is involved in a private price-fixing arrangement. The only real danger is that it will seek to further purely parochial public interests at the expense of more overriding state goals.” 471 U. S., at 47. Hallie further observed that municipalities are electorally accountable and lack the kind of private incentives characteristic of active participants in the market. See id., at 45, n. 9. Critically, the municipality in Hallie exercised a wide range of governmental powers across different economic spheres, substantially reducing the risk that it would pursue private interests while regulating any single field. See ibid. That Hallie excused municipalities from Midcal’s supervision rule for these reasons all but confirms the rule’s applicability to actors controlled by active market participants, who ordinarily have none of the features justifying the narrow exception Hallie identified. See 471 U. S., at 45.

Following Goldfarb, Midcal, and Hallie, which clarified the conditions under which Parker immunity attaches to the conduct of a nonsovereign actor, the Court in Columbia v. Omni Outdoor Advertising, Inc.,499 U. S. 365, addressed whether an otherwise immune entity could lose immunity for conspiring with private parties. In Omni, an aspiring billboard merchant argued that the city of Columbia, South Carolina, had violated the Sherman Act—and forfeited its Parker immunity—by anticompetitively conspiring with an established local company in passing an ordinance restricting new billboard construction. 499 U. S., at 367–368. The Court disagreed, holding there is no “conspiracy exception” to Parker. Omni, supra, at 374.

Omni, like the cases before it, recognized the importance of drawing a line “relevant to the purposes of the Sherman Act and of Parker: prohibiting the restriction of competition for private gain but permitting the restriction of competition in the public interest.” 499 U. S., at 378. In the context of a municipal actor which, as in Hallie, exercised substantial governmental powers, Omni rejected a conspiracy exception for “corruption” as vague and unworkable, since “virtually all regulation benefits some segments of the society and harms others” and may in that sense be seen as “ ‘corrupt.’ ” 499 U. S., at 377. Omni also rejected subjective tests for corruption that would force a “deconstruction of the governmental process and probing of the official ‘intent’ that we have consistently sought to avoid.” Ibid. Thus, whereas the cases preceding it addressed the preconditions of Parker immunity and engaged in an objective, ex ante inquiry into nonsovereign actors’ structure and incentives, Omni made clear that recipients of immunity will not lose it on the basis of ad hoc and ex post questioning of their motives for making particular decisions.

Omni’s holding makes it all the more necessary to ensure the conditions for granting immunity are met in the first place. The Court’s two state-action immunity cases decided after Omni reinforce this point. In Ticor the Court affirmed that Midcal’s limits on delegation must ensure that “[a]ctual state involvement, not deference to private price-fixing arrangements under the general auspices of state law, is the precondition for immunity from federal law.” 504 U. S., at 633. And in Phoebe Putney the Court observed that Midcal’s active supervision requirement, in particular, is an essential condition of state-action immunity when a nonsovereign actor has “an incentive to pursue [its] own self-interest under the guise of implementing state policies.” 568 U. S., at ___ (slip op., at 8) (quoting Hallie, supra, at 46–47). The lesson is clear: Midcal’s active supervision test is an essential prerequisite of Parker immunity for any nonsovereign entity—public or private—controlled by active market participants.

C

The Board argues entities designated by the States as agencies are exempt from Midcal’s second requirement. That premise, however, cannot be reconciled with the Court’s repeated conclusion that the need for supervision turns not on the formal designation given by States to regulators but on the risk that active market participants will pursue private interests in restraining trade.

State agencies controlled by active market participants, who possess singularly strong private interests, pose the very risk of self-dealing Midcal’s supervision requirement was created to address. See Areeda & Hovencamp ¶227, at 226. This conclusion does not question the good faith of state officers but rather is an assessment of the structural risk of market participants’ confusing their own interests with the State’s policy goals. See Patrick, 486 U. S., at 100–101.

The Court applied this reasoning to a state agency in Goldfarb. There the Court denied immunity to a state agency (the Virginia State Bar) controlled by market participants (lawyers) because the agency had “joined in what is essentially a private anticompetitive activity” for “the benefit of its members.” 421 U. S., at 791, 792. This emphasis on the Bar’s private interests explains why Goldfarb, though it predates Midcal, considered the lack of supervision by the Virginia Supreme Court to be a principal reason for denying immunity. See 421 U. S., at 791; see also Hoover, 466 U. S., at 569 (emphasizing lack of active supervision in Goldfarb); Bates v. State Bar of Ariz.,433 U. S. 350–362 (1977) (granting the Arizona Bar state-action immunity partly because its “rules are subject to pointed re-examination by the policymaker”).

While Hallie stated “it is likely that active state supervision would also not be required” for agencies, 471 U. S., at 46, n. 10, the entity there, as was later the case in Omni, was an electorally accountable municipality with general regulatory powers and no private price-fixing agenda. In that and other respects the municipality was more like prototypical state agencies, not specialized boards dominated by active market participants. In important regards, agencies controlled by market participants are more similar to private trade associations vested by States with regulatory authority than to the agencies Hallie considered. And as the Court observed three years after Hallie, “[t]here is no doubt that the members of such associations often have economic incentives to restrain competition and that the product standards set by such associations have a serious potential for anticompetitive harm.” Allied Tube, 486 U. S., at 500. For that reason, those associations must satisfy Midcal’s active supervision standard. See Midcal, 445 U. S., at 105–106.

The similarities between agencies controlled by active market participants and private trade associations are not eliminated simply because the former are given a formal designation by the State, vested with a measure of government power, and required to follow some procedural rules. See Hallie, supra, at 39 (rejecting “purely formalistic” analysis). Parker immunity does not derive from nomenclature alone. When a State empowers a group of active market participants to decide who can participate in its market, and on what terms, the need for supervision is manifest. See Areeda & Hovencamp ¶227, at 226. The Court holds today that a state board on which a controlling number of decisionmakers are active market participants in the occupation the board regulates must satisfy Midcal’s active supervision requirement in order to invoke state-action antitrust immunity.

D

The State argues that allowing this FTC order to stand will discourage dedicated citizens from serving on state agencies that regulate their own occupation. If this were so—and, for reasons to be noted, it need not be so—there would be some cause for concern. The States have a sovereign interest in structuring their governments, see Gregory v. Ashcroft,501 U. S. 452,460 (1991), and may conclude there are substantial benefits to staffing their agencies with experts in complex and technical subjects, see Southern Motor Carriers Rate Conference, Inc. v. United States,471 U. S. 48,64 (1985). There is, moreover, a long tradition of citizens esteemed by their professional colleagues devoting time, energy, and talent to enhancing the dignity of their calling.

Adherence to the idea that those who pursue a calling must embrace ethical standards that derive from a duty separate from the dictates of the State reaches back at least to the Hippocratic Oath. See generally S. Miles, The Hippocratic Oath and the Ethics of Medicine (2004). In the United States, there is a strong tradition of professional self-regulation, particularly with respect to the development of ethical rules. See generally R. Rotunda & J. Dzienkowski, Legal Ethics: The Lawyer’s Deskbook on Professional Responsibility (2014); R. Baker, Before Bioethics: A History of American Medical Ethics From the Colonial Period to the Bioethics Revolution (2013). Dentists are no exception. The American Dental Association, for example, in an exercise of “the privilege and obligation of self-government,” has “call[ed] upon dentists to follow high ethical standards,” including “honesty, compassion, kindness, integrity, fairness and charity.” American Dental Association, Principles of Ethics and Code of Professional Conduct 3–4 (2012). State laws and institutions are sustained by this tradition when they draw upon the expertise and commitment of professionals.

Today’s holding is not inconsistent with that idea. The Board argues, however, that the potential for money damages will discourage members of regulated occupations from participating in state government. Cf. Filarsky v. Delia, 566 U. S. ___, ___ (2012) (slip op., at 12) (warning in the context of civil rights suits that the “the most talented candidates will decline public engagements if they do not receive the same immunity enjoyed by their public employee counterparts”). But this case, which does not present a claim for money damages, does not offer occasion to address the question whether agency officials, including board members, may, under some circumstances, enjoy immunity from damages liability. See Goldfarb, 421 U. S., at 792, n. 22; see also Brief for Respondent 56. And, of course, the States may provide for the defense and indemnification of agency members in the event of litigation.

States, furthermore, can ensure Parker immunity is available to agencies by adopting clear policies to displace competition; and, if agencies controlled by active market participants interpret or enforce those policies, the States may provide active supervision. Precedent confirms this principle. The Court has rejected the argument that it would be unwise to apply the antitrust laws to professional regulation absent compliance with the prerequisites for invoking Parker immunity:

“[Respondents] contend that effective peer review is essential to the provision of quality medical care and that any threat of antitrust liability will prevent physicians from participating openly and actively in peer-review proceedings. This argument, however, essentially challenges the wisdom of applying the antitrust laws to the sphere of medical care, and as such is properly directed to the legislative branch. To the extent that Congress has declined to exempt medical peer review from the reach of the antitrust laws, peer review is immune from antitrust scrutiny only if the State effectively has made this conduct its own.” Patrick, 486 U. S. at 105–106 (footnote omitted).

The reasoning of Patrick v. Burget applies to this case with full force, particularly in light of the risks licensing boards dominated by market participants may pose to the free market. See generally Edlin & Haw, Cartels by Another Name: Should Licensed Occupations Face Antitrust Scrutiny? 162 U. Pa. L. Rev. 1093 (2014).

E

The Board does not contend in this Court that its anticompetitive conduct was actively supervised by the State or that it should receive Parker immunity on that basis.

By statute, North Carolina delegates control over the practice of dentistry to the Board. The Act, however, says nothing about teeth whitening, a practice that did not exist when it was passed. After receiving complaints from other dentists about the nondentists’ cheaper services, the Board’s dentist members—some of whom offered whitening services—acted to expel the dentists’ competitors from the market. In so doing the Board relied upon cease-and-desist letters threatening criminal liability, rather than any of the powers at its disposal that would invoke oversight by a politically accountable official. With no active supervision by the State, North Carolina officials may well have been unaware that the Board had decided teeth whitening constitutes “the practice of dentistry” and sought to prohibit those who competed against dentists from participating in the teeth whitening market. Whether or not the Board exceeded its powers under North Carolina law, cf. Omni, 499 U. S., at 371–372, there is no evidence here of any decision by the State to initiate or concur with the Board’s actions against the nondentists.

IV

The Board does not claim that the State exercised active, or indeed any, supervision over its conduct regarding nondentist teeth whiteners; and, as a result, no specific supervisory systems can be reviewed here. It suffices to note that the inquiry regarding active supervision is flexible and context-dependent. Active supervision need not entail day-to-day involvement in an agency’s operations or micromanagement of its every decision. Rather, the question is whether the State’s review mechanisms provide “realistic assurance” that a nonsovereign actor’s anticompetitive conduct “promotes state policy, rather than merely the party’s individual interests.” Patrick, supra, at 100–101; see also Ticor, 504 U. S., at 639–640.

The Court has identified only a few constant requirements of active supervision: The supervisor must review the substance of the anticompetitive decision, not merely the procedures followed to produce it, see Patrick, 486 U. S., at 102–103; the supervisor must have the power to veto or modify particular decisions to ensure they accord with state policy, see ibid.; and the “mere potential for state supervision is not an adequate substitute for a decision by the State,” Ticor, supra, at 638. Further, the state supervisor may not itself be an active market participant. In general, however, the adequacy of supervision otherwise will depend on all the circumstances of a case.

*  *  *

The Sherman Act protects competition while also respecting federalism. It does not authorize the States to abandon markets to the unsupervised control of active market participants, whether trade associations or hybrid agencies. If a State wants to rely on active market participants as regulators, it must provide active supervision if state-action immunity under Parker is to be invoked.

The judgment of the Court of Appeals for the Fourth Circuit is affirmed.

It is so ordered.