opinion: Justice Ginsburg
  announced the judgment of the Court and delivered the opinion of the Court with respect to Parts I, II, and III-A, and an opinion with respect to Part III-B, in which Justice O’Connor, Justice Souter, and Justice Breyer join.
  This case concerns the proper construction of the anti-discrimination provision contained in the public services portion (Title II) of the Americans with Disabilities Act of 1990 (ADA), 104 Stat. 337, 42 U. S. C. §12132. Specifically, we confront the question whether the proscription of discrimination may require placement of persons with mental disabilities in community settings rather than in institutions. The answer, we hold, is a qualified yes. Such action is in order when the State’s treatment professionals have determined that community placement is appropriate, the transfer from institutional care to a less restrictive setting is not opposed by the affected individual, and the placement can be reasonably accommodated, taking into account the resources available to the State and the needs of others with mental disabilities. In so ruling, we affirm the decision of the Eleventh Circuit in substantial part. We remand the case, however, for further consideration of the appropriate relief, given the range of facilities the State maintains for the care and treatment of persons with diverse mental disabilities, and its obligation to administer services with an even hand.
  I
  This case, as it comes to us, presents no constitutional question. The complaints filed by plaintiffs-respondents L. C. and E. W. did include such an issue; L. C. and E. W. alleged that defendants-petitioners, Georgia health care officials, failed to afford them minimally adequate care and freedom from undue restraint, in violation of their rights under the Due Process Clause of the Fourteenth Amendment. See Complaint ¶¶ 87-91; Intervenor’s Complaint ¶¶ 30-34. But neither the District Court nor the Court of Appeals reached those Fourteenth Amendment claims. See Civ. No. 1:95-cv-1210-MHS (ND Ga., Mar. 26,1997), pp. 5-6, 11-13, App. to Pet. for Cert. 34a-35a, 40a-41a; 138 F. 3d 893, 895, and n. 3 (CA11 1998). Instead, the courts below resolved the case solely on statutory grounds. Our review is similarly confined. Cf. Cleburne v. Cleburne Living Center, Inc., 473 U. S. 432, 450 (1985) (Texas city’s requirement of special use permit for operation of group home for mentally retarded, when other care and multiple-dwelling facilities were freely permitted, lacked rational basis and therefore violated Equal Protection Clause of Fourteenth Amendment). Mindful that it is a statute we are construing, we set out first the legislative and regulatory prescriptions on which the case turns.
  In the opening provisions of the ADA, Congress stated findings applicable to the statute in all its parts. Most relevant to this case, Congress determined that
  “(2) historically, society has tended to isolate and segregate individuals with disabilities, and, despite some improvements, such forms of discrimination against individuals with disabilities continue to be a serious and pervasive social problem;
  “(3) discrimination against individuals with disabilities persists in such critical areas as ... institutionalization ...;
  “(5) individuals with disabilities continually encounter various forms of discrimination, including outright intentional exclusion, . . . failure to make modifications to existing facilities and practices, . . . [and] segregation ...42 U. S. C. §§ 12101(a)(2), (3), (5).
  Congress then set forth prohibitions against discrimination in employment (Title I, §§ 12111-12117), public services furnished by governmental entities (Title II, §§12131-12165), and public accommodations provided by private entities (Title III, §§12181-12189). The statute as a whole is intended “to provide a clear and comprehensive national mandate for the elimination of discrimination against individuals with disabilities.” § 12101(b)(1).
  This case concerns Title II, the public services portion of the ADA. The provision of Title II centrally at issue reads:
  “Subject to the provisions of this subehapter, no qualified individual with a disability shall, by reason of such disability, be excluded from participation in or be denied the benefits of the services, programs, or activities of a public entity, or be subjected to discrimination by any such entity.” §201, as set forth in 42 U. S. C. §12182.
  Title IFs definition section states that “public entity” includes “any State or local government,” and “any department, agency, [or] special purpose district.” §§ 12131(1)(A), (B). The same section defines “qualified individual with a disability” as
  “an individual with a disability who, with or without reasonable modifications to rules, policies, or practices, the removal of architectural, communication, or transportation barriers, or the provision of auxiliary aids and services, meets the essential eligibility requirements for the receipt of services or the participation in programs or activities provided by a public entity.” § 12131(2).
  On redress for violations of §12132’s discrimination prohibition, Congress referred to remedies available under § 505 of the Rehabilitation Act of 1973, 92 Stat. 2982, 29 U. S. C. § 794a. See §203, as set forth in 42 U. S. C. § 12133 (“The remedies, procedures, and rights set forth in [§505 of the Rehabilitation Act] shall be the remedies, procedures, and rights this subchapter provides to any person alleging discrimination on the basis of disability in violation of section 12132 of this title.”).
  Congress instructed the Attorney General to issue regulations implementing provisions of Title II, including § 12132’s discrimination proscription. See § 204, as set forth in § 12134(a) (“[T]he Attorney General shall promulgate regulations in an accessible format that implement this part.”). The Attorney GeneraFs regulations, Congress further directed, “shall be consistent with this chapter and with the coordination regulations ... applicable to recipients of Federal financial assistance under [§504 of the Rehabilitation Act].” §204, as set forth in 42 U. S. C. § 12134(b). One of the § 504 regulations requires recipients of federal funds to “administer programs and activities in the most integrated setting appropriate to the needs of qualified handicapped persons.” 28 CFR § 41.51(d) (1998).
  As Congress instructed, the Attorney General issued Title II regulations, see 28 CFR pt. 35 (1998), including one modeled on the § 504 regulation just quoted; called the “integration regulation,” it reads:
  “A public entity shall administer services, programs, and activities in the most integrated setting appropriate to the needs of qualified individuals -with disabilities.” 28 CFR § 35.130(d) (1998).
  The preamble to the Attorney General’s Title II regulations defines “the most integrated setting appropriate to the needs of qualified individuals with disabilities” to mean “a setting that enables individuals with disabilities to interact with non-disabled persons to the fullest extent possible.” 28 CFR pt. 35, App. A, p. 450 (1998). Another regulation requires public entities to “make reasonable modifications” to avoid “discrimination on the basis of disability,” unless those modifications would entail a “fundamental] alter[ation]”; called here the “reasonable-modifications regulation,” it provides:
  “A public entity shall make reasonable modifications in policies, practices, or procedures when the modifications are necessary to avoid discrimination on the basis of disability, unless the public entity can demonstrate that making the modifications would fundamentally alter the nature of the service, program, or activity.” 28 CFR § 35.130(b)(7) (1998).
  We recite these regulations with the caveat that we do not here determine their validity. While the parties differ on the proper construction and enforcement of the regulations, we do not understand petitioners to challenge the regulatory formulations themselves as outside the congressional authorization. See Brief for Petitioners 16-17, 36, 40-41; Reply Brief 15-16 (challenging the Attorney General’s interpretation of the integration regulation).
  II
  With the key legislative provisions in full view, we summarize the facts underlying this dispute. Respondents L. C. and E. W. are mentally retarded women; L. C. has also been diagnosed with schizophrenia, and E. W. with a personality disorder. Both women have a history of treatment in institutional settings. In May 1992, L. C. was voluntarily admitted to Georgia Regional Hospital at Atlanta (GRH), where she was confined for treatment in a psychiatric unit. By May 1993, her psychiatric condition had stabilized, and L. C.’s treatment team at GRH agreed that her needs could be met appropriately in one of the community-based programs the State supported. Despite this evaluation, L. C. remained institutionalized until February 1996, when the State plaeed her in a community-based treatment program.
  E. W. was voluntarily admitted to GRH in February 1995; like L. C., E. W. was confined for treatment in a psychiatric unit. In March 1995, GRH sought to discharge E. W. to a homeless shelter, but abandoned that plan after her attorney filed an administrative complaint. By 1996, E. W.’s treating psychiatrist concluded that she could be treated appropriately in a community-based setting. She nonetheless remained institutionalized until a few months after the District Court issued its judgment in this case in 1997.
  In May 1995, when she was still institutionalized at GRH, L. C. filed suit in the United States District Court for the Northern District of Georgia, challenging her continued confinement in a segregated environment. Her complaint invoked 42 U. S. C. § 1983 and provisions of the ADA, §§ 12131-12134, and named as defendants, now petitioners, the Commissioner of the Georgia Department of Human Resources, the Superintendent of GRH, and the Executive Director of the Fulton County Regional Board (collectively, the State). L. C. alleged that the State’s failure to place her in a community-based program, once her treating professionals determined that such placement was appropriate, violated, inter alia, Title II of the ADA. L. C.’s pleading requested, among other things, that the State place her in a community care residential program, and that she receive treatment with the ultimate goal of integrating her into the mainstream of society. E. W. intervened in the action, stating an identical claim.
  The District Court granted partial summary judgment in favor of L. C. and E. W. See App. to Pet. for Cert. 31a-42a. The court held that the State’s failure to place L. C. and E. W. in an appropriate community-based treatment program violated Title II of the ADA. See id., at 39a, 41a. In so ruling, the court rejected the State’s argument that inadequate funding, not discrimination against L. C. and E. W. “by reason of” their disabilities, accounted for their retention at GRH. Under Title II, the court concluded, "unnecessary institutional segregation of the disabled constitutes discrimination per se, which cannot be justified by a lack of funding.” Id., at 37a.
  In addition to contending that L. C. and E. W. had not shown discrimination “by reason of [their] disabilities],” the State resisted court intervention on the ground that requiring immediate transfers in cases of this order would “fundamentally alter” the State’s activity. The State reasserted that it was already using all available funds to provide services to other persons with disabilities. See id., at 38a. Rejecting the State’s “fundamental alteration” defense, the court observed that existing state programs provided community-based treatment of the kind for which L. C. and E. W. qualified, and that the State could “provide services to plaintiffs in the community at considerably less cost than is required to maintain them in an institution.” Id., at 39a.
  The Court of Appeals for the Eleventh Circuit affirmed the judgment of the District Court, but remanded for reassessment of the State’s cost-based defense. See 138 F. 3d, at 905. As the appeals court read the statute and regulations: When “a disabled individual’s treating professionals find that a community-based placement is appropriate for that individual, the ADA imposes a duty to provide treatment in a community setting — the most integrated setting appropriate to that patient’s needs”; “[w]here there is no such finding [by the treating professionals], nothing in the ADA requires the deinstitutionalization of th[e] patient.” Id., at 902.
  The Court of Appeals recognized that the State’s duty to provide integrated services “is not absolute”; under the Attorney General’s Title II regulation, “reasonable modifications” were required of the State, but fundamental alterations were not demanded. Id., at 904. The appeals court thought it clear, however, that “Congress wanted to permit a cost defense only in the most limited of circumstances.” Id., at 902. In conclusion, the court stated that a cost justification would fail “[u]nless the State can prove that requiring it to [expend additional funds in order to provide L, C. and E. W. with integrated services] would be so unreasonable given the demands of the State’s mental health budget that it would fundamentally alter the service [the State] provides.” Id., at 905. Because it appeared that the District Court had entirely ruled out a “lack of funding” justification, see App. to Pet. for Cert. 37a, the appeals court remanded, repeating that the District Court should consider, among other things, “whether the additional expenditures necessary to treat L. C. and E. W. in community-based care would be unreasonable given the demands of the State’s mental health budget.” 138 F. 3d, at 905.
  We granted certiorari in view of the importance of the question presented to the States and affected individuals. See 525 U. S. 1054 (1998).
  III
  Endeavoring to carry out Congress’ instruction to issue regulations implementing Title II, the Attorney General, in the integration and reasonable-modifications regulations, see supra, at 591-592, made two key determinations. The first concerned the scope of the ADA’s discrimination proscription, 42 U. S. C. § 12132; the second concerned the obligation of the States to counter discrimination. As to the first, the Attorney General concluded that unjustified placement or retention of persons in institutions, severely limiting their exposure to the outside community, constitutes a form of discrimination based on disability prohibited by Title II. See 28 CFR § 35.130(d) (1998) (“A public entity shall administer services ... in the most integrated setting appropriate to the needs of qualified individuals with disabilities.”); Brief for United States as Amicus Curiae in Helen L. v. DiDario, No. 94-1243 (CA3 1994), pp. 8, 15-16 (unnecessary segregation of persons with disabilities constitutes a form of discrimination prohibited by the ADA and the integration regulation). Regarding the States’ obligation to avoid unjustified isolation of individuals with disabilities, the Attorney General provided that States could resist modifications that “would fundamentally alter the nature of the service, program, or activity.” 28 CFR § 35.130(b)(7) (1998).
  The Court of Appeals essentially upheld the Attorney General’s construction of the ADA. As just recounted, see supra, at 595-596, the appeals court ruled that the unjustified institutionalization of persons with mental disabilities violated Title II; the court then remanded with instructions to measure the cost of caring for L. C. and E. W. in a community-based facility against the State’s mental health budget.
  We affirm the Court of Appeals’ decision in substantial part. Unjustified isolation, we hold, is properly regarded as discrimination based on disability. But we recognize, as well, the States’ need to maintain a range of facilities for the care and treatment of persons with diverse mental disabilities, and the States’ obligation to administer services with an even hand. Accordingly, we further hold that the Court of Appeals’ remand instruction was unduly restrictive. In evaluating a State’s fundamental-alteration defense, the District Court must consider, in view of the resources available to the State, not only the cost of providing community-based care to the litigants, but also the range of services the State provides others with mental disabilities, and the State’s obligation to mete out those services equitably.
  A
  We examine first whether, as the Eleventh Circuit held, undue institutionalization qualifies as discrimination “by reason of . . . disability.” The Department of Justice has consistently advocated that it does. Because the Department is the agency directed by Congress to issue regulations implementing Title II, see supra, at 591-592, its views warrant respect. We need not inquire whether the degree of deference described in Chevron U. S. A. Inc. v. Natural Resources Defense Council, Inc., 467 U. S. 887, 844 (1984), is in order; “Bit is enough to observe that the well-reasoned views of the agencies implementing a statute ‘constitute a body of experience and informed judgment to which courts and litigants may properly resort for guidance.’ ” Bragdon v. Abbott, 524 U. S. 624, 642 (1998) (quoting Skidmore v. Swift & Co., 323 U. S. 134, 139-140 (1944)).
  The State argues that L. C. and E. W. encountered no discrimination “by reason of” their disabilities because they were not denied community placement on account of those disabilities. See Brief for Petitioners 20. Nor were they subjected to “discrimination,” the State contends, because “‘discrimination’ necessarily requires uneven treatment of similarly situated individuals,” and L. C. and E. W. had identified no comparison class, i. e., no similarly situated individuals given preferential treatment. Id., at 21. We are satisfied that Congress had a more comprehensive view of the concept of discrimination advanced in the ADA.
  The ADA stepped up earlier measures to secure opportunities for people with developmental disabilities to enjoy the benefits of community living. The Developmentally Disabled Assistance and Bill of Rights Act, a 1975 measure, stated in aspirational terms that “[t]he treatment, services, and habilitation for a person with developmental disabilities . . . should be provided in the setting that is least restrictive of the person’s personal liberty.” 89 Stat. 502, 42 U. S. C. §6010(2) (1976 ed.) (emphasis added); see also Pennhurst State School and Hospital v. Halderman, 451 U. S. 1, 24 (1981) (concluding that the § 6010 provisions “were intended to be hortatory, not mandatory”). In a related legislative endeavor, the Rehabilitation Act of 1973, Congress used mandatory language to proscribe discrimination against persons with disabilities. See 87 Stat. 394, as amended, 29 U. S. C. §794 (1976 ed.) (“No otherwise qualified individual with a disability in the United States . . . shall, solely by reason of her or his disability, be excluded from the participation in, be denied the benefits of, or be subjected to discrimination under any program or activity receiving Federal financial assistance.” (Emphasis added.)) Ultimately, in the ADA, enacted in 1990, Congress not only required all public entities to refrain from discrimination, see 42 U. S. C. § 12132; additionally, in findings applicable to the entire statute, Congress explicitly identified unjustified “segregation” of persons with disabilities as a “for[m] of discrimination.” See § 12101(a)(2) (“historically, society has tended to isolate and segregate individuals with disabilities, and, despite some improvements, such forms of discrimination against individuals with disabilities continue to be a serious and pervasive social problem”); § 12101(a)(5) (“individuals with disabilities continually encounter various forms of discrimination, including ... segregation”).
  Recognition that unjustified institutional isolation of persons with disabilities is a form of discrimination reflects two evident judgments. First, institutional placement of persons who can handle and benefit from community settings perpetuates unwarranted assumptions that persons so isolated are incapable or unworthy of participating in community life. Cf. Allen v. Wright, 468 U. S. 737, 755 (1984) (“There can be no doubt that [stigmatizing injury often caused by racial discrimination] is one of the most serious consequences of discriminatory government action.”); Los Angeles Dept, of Water and Power v. Manhart, 435 U. S. 702, 707, n. 13 (1978) (“ Tn forbidding employers to discriminate against individuals because of their sex, Congress intended to strike at the entire spectrum of disparate treatment of men and women resulting from sex stereotypes.’” (quoting Sprogis v. United Air Lines, Inc., 444 F. 2d 1194, 1198 (CA7 1971)). Second, confinement in an institution severely diminishes the everyday life activities of individuals, including family relations, social contacts, work options, economic independence, educational advancement, and cultural enrichment. See Brief for American Psychiatric Association et al. as Amici Curiae 20-22. Dissimilar treatment correspondingly exists in this key respect: In order to receive needed medical services, persons with mental disabilities must, because of those disabilities, relinquish participation in community life they could enjoy given reasonable accommodations, while persons without mental disabilities can receive the medical services they need without similar sacrifice. See Brief for United States as Amicus Curiae 6-7,17.
  The State urges that, whatever Congress may have stated as its findings in the ADA, the Medicaid statute “reflected a congressional policy preference for treatment in the institution over treatment in the community.” Brief for Petitioners 31. The State correctly used the past tense. Since 1981, Medicaid has provided funding for state-run home and community-based care through a waiver program. See 95 Stat. 812-818, as amended, 42 U. S. C. § 1396n(c); Brief for United States as Amicus Curiae 20-21. Indeed, the United States points out that the Department of Health and Human Services (HHS) “has a policy of encouraging States to take advantage of the waiver program, and often approves more waiver slots than a State ultimately uses.” Id., at 25-26 (further observing that, by 1996, “HHS approved up to 2109 waiver slots for Georgia, but Georgia used only 700”).
  We emphasize that nothing in the ADA or its implementing regulations condones termination of institutional settings for persons unable to handle or benefit from community settings. Title II provides only that “qualified individualfs] with a disability” may not “be subjected to discrimination.” 42 U. S. C. § 12132. “Qualified individuals,” the ADA further explains, are persons with disabilities who, “with or without reasonable modifications to rules, policies, or practices, . . . mee[t] the essential eligibility requirements for the receipt of services or the participation in programs or activities provided by a public entity.” § 12181(2).
  Consistent with these provisions, the State generally may rely on the reasonable assessments of its own professionals in determining whether an individual “meets the essential eligibility requirements” for habilitation in a community-based program. Absent such qualification, it would be inappropriate to remove a patient from the more restrictive setting. See 28 CFR § 35.130(d) (1998) (public entity shall administer services and programs in “the most integrated setting appropriate to the needs of qualified individuals with disabilities” (emphasis added)); cf. School Bd. of Nassau Cty. v. Arline, 480 U. S. 273, 288 (1987) (“[C]ourts normally should defer to the reasonable medical judgments of public health officials.”). Nor is there any federal requirement that community-based treatment be imposed on patients who do not desire it. See 28 CFR § 35.130(e)(1) (1998) (“Nothing in this part shall be construed to require an individual with a disability to accept an accommodation . . . which such individual chooses not to accept.”); 28 CFR pt. 35, App. A, p. 450 (1998) (“[P]ersons with disabilities must be provided the option of declining to accept a particular accommodation.”). In this case, however, there is no genuine dispute concerning the status of L. C. and E. W. as individuals “qualified” for noninstitutional care: The State’s own professionals determined that community-based treatment would be appropriate for L. G. and E. W., and neither woman opposed such treatment. See supra, at 593.
  B
  The State’s responsibility, once it provides community-based treatment to qualified persons with disabilities, is not boundless. The reasonable-modifications regulation speaks of "reasonable modifications” to avoid discrimination, and allows States to resist modifications that entail a “fundamenta[l] alteration]” of the States’ services and programs. 28 CFR § 35.130(b)(7) (1998). The Court of Appeals construed this regulation to permit a cost-based defense “only in the most limited of circumstances,” 138 F. 3d, at 902, and remanded to the District Court to consider, among other things, “whether the additional expenditures necessary to treat L. C. and E. W. in community-based care would be unreasonable given the demands of the State’s mental health budget,” id., at 905.
  The Court of Appeals’ construction of the reasonable-modifications regulation is unacceptable for it would leave the State virtually defenseless once it is shown that the plaintiff is qualified for the service or program she seeks. If the expense entailed in placing one or two people in a community-based treatment program is properly measured for reasonableness against the State’s entire mental health budget, it is unlikely that a State, relying on the fundamental-alteration defense, could ever prevail. See Tr. of Oral Arg. 27 (State’s attorney argues that Court of Appeals’ understanding of the fundamental-alteration defense, as expressed in its order to the District Court, “will always preclude the State from a meaningful defense”); cf. Brief for Petitioners 37-38 (Court of Appeals’ remand order “mistakenly asks the district court to examine [the fundamental-alteration] defense based on the cost of providing community care to just two individuals, not all Georgia citizens who desire community care”); 1:95— cv-1210-MHS (ND Ga., Oct. 20, 1998), p. 3, App. 177 (District Court, on remand, declares the impact of its decision beyond L. C. and E.W. “irrelevant”). Sensibly construed, the fundamental-alteration component of the reasonable-modifications regulation would allow the State to show that, in the allocation of available resources, immediate relief for the plaintiffs would be inequitable, given the responsibility the State has undertaken for the care and treatment of a large and diverse population of persons with mental disabilities.
  When it granted summary judgment for plaintiffs in this case, the District Court compared the cost of caring for the plaintiffs in a community-based setting with the cost of caring for them in an institution. That simple comparison showed that community placements cost less than institutional confinements. See App. to Pet. for Cert. 39a. As the United States recognizes, however, a comparison so simple overlooks costs the State cannot avoid; most notably, a “State . . . may experience increased overall expenses by funding community placements without being able to take advantage of the savings associated with the closure of institutions.” Brief for United States as Amicus Curiae 21.
  As already observed, see supra, at 601-602, the ADA is not reasonably read to impel States to phase out institutions, placing patients in need of close care at risk. Cf post, at 610 (Kennedy, J., concurring in judgment). Nor is it the ADA’s mission to drive States to move institutionalized patients into an inappropriate setting, such as a homeless shelter, a placement the State proposed, then retracted, for E. W. See supra, at 593. Some individuals, like L. C. and E. W. in prior years, may need institutional care from time to time “to stabilize acute psychiatric symptoms.” App. 98 (affidavit of Dr. Richard L. Elliott); see 138 F. 3d, at 903 (“[T]here may be times [when] a patient can be treated in the community, and others whe[n] an institutional placement is necessary.”); Reply Brief 19 (placement in a community-based treatment program does not mean the State will no longer need to retain hospital accommodations for the person so placed). For other individuals, no placement outside the institution may ever be appropriate. See Brief for American Psychiatric Association et al. as Amici Curiae 22-23 (“Some individuals, whether mentally retarded or mentally ill, are not prepared at particular times — perhaps in the short run, perhaps in the long run — for the risks and exposure of the less protective environment of community settings”; for these persons, “institutional settings are needed and must remain available.”); Brief for Voice of the Retarded et al. as Amici Curiae 11 (“Each disabled person is entitled to treatment in the most integrated setting possible for that person — recognizing that, on a ease-by-case basis, that setting may be in an institution.”); Youngberg v. Romeo, 457 U. S. 307, 327 (1982) (Blackmun, J., concurring) (“For many mentally retarded people, the difference between the capacity to do things for themselves within an institution and total dependence on the institution for all of their needs is as much liberty as they ever will know.”).
  To maintain a range of facilities and to administer services with an even hand, the State must have more leeway than the courts below understood the fundamental-alteration defense to allow. If, for example, the State were to demonstrate that it had a comprehensive, effectively working plan for placing qualified persons with. mental disabilities in less restrictive settings, and a waiting list that moved at a reasonable pace not controlled by the State’s endeavors to keep its institutions fully populated, the reasonable-modifications standard would be met. See Tr. of Oral Arg. 5 (State’s attorney urges that, “by asking [a] person to wait a short time until a community bed is available, Georgia does not exclude [that] person by reason of disability, neither does Georgia discriminate against her by reason of disability”); see also id., at 25 (“[I]t is reasonable for the State to ask someone to wait until a community placement is available.”). In such circumstances, a court would have no warrant effectively to order displacement of persons at the top of the community-based treatment waiting list by individuals lower down who commenced civil actions.
  * * *
  For the reasons stated, we conclude that, under Title II of the ADA, States are required to provide community-based treatment for persons with mental disabilities when the State’s treatment professionals determine that such placement is appropriate, the affected persons do not oppose such treatment, and the placement can be reasonably accommodated, taking into account the resources available to the State and the needs of others with mental disabilities. The judgment of the Eleventh Circuit is therefore affirmed in part and vacated in part, and the case is remanded for further proceedings.
  It is so ordered.
  The ABA, enacted in 1990, is the Federal Government’s most recent and extensive endeavor to address discrimination against persons with disabilities. Earlier legislative efforts included the Rehabilitation Act of 1973, 87 Stat. 355, 29 U. S. C. §701 et seq. (1976 ed.), and the Developmentally Disabled Assistance and Bill of Rights Act, 89 Stat. 486, 42 U. S. C. §6001 et seq. (1976 ed.), enacted in 1975. In the ADA, Congress for the first time referred expressly to “segregation” of persons with disabilities as a “for[m] of discrimination,” and to discrimination that persists in the area of “institutionalization.” §§ 12101(a)(2), (3), (5).
  2 The ADA defines “disability,” “with respect to an individual,” as
  “(A) a physical or mental impairment that substantially limits one or more of the major life activities of such individual;
  “(B) a record of such an impairment; or
  “(C) being regarded as having such an impairment.” § 12102(2).
  There is no dispute that L. C. and E. W. are disabled within the meaning of the ADA.
  In addition to the provisions set out in Part A governing public services generally, see §§ 12131-12134, Title II contains in Part B a host of provisions governing public transportation services, see §§ 12141-12165.
  Section 505 of the Rehabilitation Act incorporates the remedies, rights, and procedures set forth in Title VI of the Civil Rights Act of 1964 for violations of § 504 of the Rehabilitation Act. See 29 U. S. C. § 794a(a)(2). Title VI, in turn, directs each federal department authorized to extend financial assistance to any department or agency of a State to issue rules and regulations consistent with achievement of the objectives of the statute authorizing financial assistance. See 78 Stat. 252, 42 U. S. C. §2000d-1. Compliance with such requirements may be effected by the termination or denial of federal funds, or “by any other means authorized by law.” Ibid. Remedies both at law and in equity are available for violations of the statute. See §2000d-7(a)(2).
  Congress directed the Secretary of Transportation to issue regulations implementing the portion of Title II concerning public transportation. See 42 U. S. C. §§ 12143(b), 12149, 12164. As stated in the regulations, a person alleging discrimination on the basis of disability in violation of Title II may seek to enforce its provisions by commencing a private lawsuit, or by filing a complaint with (a) a federal agency that provides funding to the public entity that is the subject of the complaint, (b) the Department of Justice for referral to an appropriate agency, or (e) one of eight federal agencies responsible for investigating complaints arising under Title II: the Department of Agriculture, the Department of Education, the Department of Health and Human Services, the Department of Housing and Urban Development, the Department of the Interior, the Department of Justice, the Department of Labor, and the Department of Transportation. See 28 CFR §§ 35.170(c), 35.172(b), 35.190(b) (1998).
  The ADA contains several other provisions allocating regulatory and enforcement responsibility. Congress instructed the Equal Employment Opportunity Commission (EEOC) to issue regulations implementing Title I, see 42 U. S. C. § 12116; the EEOC, the Attorney General, and persons alleging discrimination on the basis of disability in violation of Title I may enforce its provisions, see § 12117(a). Congress similarly instructed the Secretary of Transportation and the Attorney General to issue regulations implementing provisions of Title III, see §§ 12186(a)(1), (b); the Attorney General and persons alleging discrimination on the basis of disability in violation of Title III may enforce its provisions, see §§ 12188(a)(1), (b). Each federal agency responsible for ADA implementation may render technical assistance to affected individuals and institutions with respect to provisions of the ADA for which the agency has responsibility. See § 12206(c)(1).
  L. C. and E. W. are currently receiving treatment in community-based programs. Nevertheless, the case is not moot. As the District Court and Court of Appeals explained, in view of the multiple institutional placements L. C. and E. W. have experienced, the controversy they brought to court is “capable of repetition, yet evading review.” No. 1:95-cv-1210-MHS (ND Ga., Mar. 26, 1997), p. 6, App. to Pet. for Cert. 35a (internal quotation marks omitted); see 138 F. 3d 893, 895, n. 2 (CA11 1998) (citing Honig v. Doe, 484 U, S. 305, 318-323 (1988), and Vitek v. Jones, 445 U. S. 480, 486-487 (1980)).
  After this Court granted certiorari, the District Court issued a decision on remand rejecting the State’s fundamental-alteration defensa See 1:95-cv-1210-MHS (ND Ga., Jan. 29, 1999), p. 1. The court concluded that the annual cost to the State of providing community-based treatment to L. C. and E. W. was not unreasonable in relation to the State’s overall mental health budget. See id., at 5. In reaching that judgment, the District Court first declared “irrelevant” the potential impact of its decision beyond L. C. and E. W. l:95-cv-1210-MHS (ND Ga., Oct. 20, 1998), p. 3, App. 177. The District Court’s decision on remand is now pending appeal before the Eleventh Circuit.
  Twenty-two States and the Territory of Guam joined a brief urging that certiorari be granted. Ten of those States joined a brief in support of petitioners on the merits.
  See Brief for United States in Halderman v. Pennhurst State School and Hospital, Nos. 78-1490,78-1564,78-1602 (CA3 1978), p. 45 (“[I]nstitu-tionalization residt[ing] in separation of mentally retarded persons for no permissible reason ... is ‘discrimination,’ and a violation of Section 504 [of the Rehabilitation Act] if it is supported by federal funds.”); Brief for United States in Halderman v. Pennhurst State School and Hospital, Nos. 78-1490, 78-1564, 78-1602 (CA3 1981), p. 27 (“Pennsylvania violates Section 504 by indiscriminately subjecting handicapped persons to [an institution] without first making an individual reasoned professional judgment as to the appropriate placement for each such person among all available alternatives.”); Brief for United States as Amicus Curiae in Helen L. v. DiDario, No. 94-1243 (CA3 1994), p. 7 (“Both the Section 504 coordination regulations and the rest of the ADA make clear that the unnecessary segregation of individuals with disabilities in the provision of public services is itself a form of discrimination within the meaning of those statutes.”); id., at 8-16.
  The dissent is driven by the notion that “this Court has never endorsed an interpretation of the term ‘discrimination’ that encompassed disparate treatment among members of the same protected class,” post, at 616 (opinion of Thomas, J.), that “[o]ur decisions construing various statutory prohibitions against ‘discrimination’ have not wavered from this path,” post, at 616, and that “a plaintiff cannot prove ‘discrimination’ by demonstrating that one member of a particular protected group has been favored over another member of that same group,” post, at 618. The dissent is incorrect as a matter of precedent and logic. See O'Connor v. Consolidated Coin Caterers Corp., 517 U. S. 308, 312 (1996) (The Age Discrimination in Employment Act of 1967 “does not ban discrimination against employees because they are aged 40 or older; it bans discrimination against employees because of their age, but limits the protected class to those who are 40 or older. The fact that one person in the protected class has lost out to another person in the protected class is thus irrelevant, so long as he has lost out because of his age.”); cf. Oncale v. Sundowner Offshore Services, Inc., 523 U. S. 75, 76 (1998) (“[W]orkplace harassment can violate Title VII’s prohibition against ‘discriminatfion] . . . because of . . . sex,’ 42 U.S.C. §2000e-2(a)(1), when the harasser and the harassed employee are of the same sex.”); Jefferies v. Harris County Community Action Assn., 615 F. 2d 1025, 1032 (CA5 1980) (“[D]iscrimination against black females can exist even in the absence of discrimination against black men or white women.”).
  Unlike the ADA, § 504 of the Rehabilitation Act contains no express recognition that isolation or segregation of persons with disabilities is a form of discrimination. Section 504’s discrimination proscription, a single sentence attached to vocational rehabilitation legislation, has yielded divergent court interpretations. See Brief for United States as Amicus Curiae 23-25.
  The waiver program provides Medicaid reimbursement to States for the provision of community-based services to individuals who would otherwise require institutional care, upon a showing that the average annual cost of such services is not more than the annual cost of institutional services. See § 1396n(c).
  Georgia law also expresses a preference for treatment in the most integrated setting appropriate. See Ga. Code Ann. §37-4-121 (1995) (“It is the policy of the state that the least restrictive alternative placement be secured for every client at every stage of his habilitation. It shall be the duty of the facility to assist the client in securing placement in noninstitutional community facilities and programs.”).
  We do not in this opinion hold that the ADA imposes on the States a "standard of care” for whatever medical services they render, or that the ADA requires States to “provide a certain level of benefits to individuals with disabilities.” Cf. post, at 623, 624 (Thomas, J., dissenting). We do hold, however, that States must adhere to the ADA’s nondiscrimination requirement with regard to the services they in fact provide.
  Even if States eventually were able to close some institutions in response to an increase in the number of community placements, the States would still incur the cost of running partially full institutions in the interim. See Brief for United States as Amicus Curiae 21.
  We reject the Court of Appeals’ construction of the reasonable-modifications regulation for another reason. The Attorney General’s Title II regulations, Congress ordered, “shall be consistent with” the regulations in part 41 of Title 28 of the Code of Federal Regulations implementing § 504 of the Rehabilitation Act. 42 U. S. C. § 12184(b). The § 504 regulation upon which the reasonable-modifications regulation is based provides now, as it did at the time the ADA was enacted:
  “A recipient shall make reasonable accommodation to the known physical or mental limitations of an otherwise qualified handicapped applicant or employee unless the recipient can demonstrate that the accommodation would impose an undue hardship on the operation of its program.” 28 CFR §41.53 (1990 and 1998 eds.).
  While the part 41 regulations do not define “undue hardship,” other §504 regulations make dear that the “undue hardship” inquiry requires not simply an assessment of the cost of the accommodation in relation to the recipient’s overall budget, but a “ease-by-case analysis weighing factors that include: (1) [t]he overall size of the recipient’s program with respect to number of employees, number and type of facilities, and size of budget; (2) [t]he type of the recipient’s operation, including the composition and structure of the recipient’s workforce; and (3) [t]he nature and cost of the accommodation needed.” 28 CFR § 42.511(c) (1998); see 45 CFR § 84.12(c) (1998) (same).
  Under the Court of Appeals’ restrictive reading, the reasonable-modifications regulation would impose a standard substantially more difficult for the State to meet than the “undue burden” standard imposed by the corresponding §504 regulation.
  This Court has recognized that two forms of discrimination are prohibited under Title VII: disparate treatment and disparate impact. See Griggs, 401 U. S., at 431 (“The Act proscribes not only overt discrimination but also practices that are fair in form, but discriminatory in operation”). Both forms of “discrimination” require a comparison among classes of employees.
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