Opinion by Judge DAVID R. THOMPSON; Dissent by Judge SNEED.

OVERVIEW

Eighteen hospitals located outside of California (“the plaintiffs”) brought suit against S. Kimberly Belshe (“Belshe”), Director of the California Department of Health Services (“CDHS”). The plaintiffs alleged that CDHS’s method for reimbursing out-of-state hospitals that treat California’s Medicaid (“Medi-Cal”) patients violates the portion of the Social Security Act known as the Boren Amendment, 42 U.S.C.A. § 1396a(a)(13)(A) (West 1992). Belshe moved for summary judgment.

In its first summary judgment order, the district court held the Boren Amendment applies to out-of-state hospitals. Thereafter, in a second order, the district court held the CDHS was failing to meet the Boren Amendment’s requirements in setting reimbursement rates for out-of-state hospitals that treat Medi-Cal patients. The court also held the CDHS is obligated to make additional payments to out-of-state hospitals treating Medi-Cal patients that serve a disproportionate share of low-income individuals (“DSH payments”). The district court then certified its summary judgment orders for immediate appeal pursuant to 28 U.S.C. § 1292 (b), and this appeal followed.

*1093 In this appeal, Belshe argues the plaintiffs’ lawsuit is mo.ot because the Boren Amendment was repealed during the pen-dency of the action, and in any event, the lawsuit is barred by the Eleventh Amendment. Alternatively, Belshe contends that the district court erred in holding that the Boren Amendment applies to out-of-state hospitals. We have jurisdiction under 28 U.S.C. § 1292 (b), and we affirm.

BACKGROUND

Title XIX of the Social Security Act, 42 U.S.C. §§ 1396 et seq. (“the Medicaid Act”), authorizes the payment of federal funds to states to defray expenses incurred in providing medical assistance to low-income individuals. See 42 U.S.C. § 1396 ; Wilder v. Virginia Hosp. Ass’n, 496 U.S. 498, 502 , 110 S.Ct. 2510 , 110 L.Ed.2d 455 (1990). Unlike Medicare, which is administered nationally, the Medicaid Act is administered by the individual states that choose to participate in the program. If a state participates in the program, the state must comply with the requirements of the Medicaid Act and its implementing regulations. See 42 U.S.C. § 1396a; 42 C.F.R. §§ 430 et seq.; Wilder, 496 U.S. at 502 , 110 S.Ct. 2510 . All fifty states have chosen to participate.

States wishing to receive Medicaid funds must submit a state medical assistance plan to the Secretary of Health and Human Services (“Secretary”). This plan must detail the state’s coverage and include the methodology it will use to reimburse institutional health care providers for the services they render to Medicaid recipients. See 42 U.S.C. § 1396a(a); 42 C.F.R. §§ 430.10 — 430.18; Wilder, 496 U.S. at 502 , 110 S.Ct. 2510 . The plan must be approved by the Health Care Financing Administration (“HCFA”), the federal agency responsible for administering the Medicaid program. See 42 C.F.R. §§ 430.10 , 430.12.

Prior to 1980, states were required to reimburse hospitals the “reasonable cost” of providing inpatient services, generally in the form of retrospective payments based on a hospital’s actual costs for given services. See 42 U.S.C. § 1396a(a)(13) (1976); Folden v. Washington State Dep’t of Social and Health Serv., 981 F.2d 1054, 1056 (9th Cir.1992). Hoping to contain escalating medical costs, Congress enacted a new standard for hospital reimbursement as part of the 1981- Omnibus Reconciliation Act, Pub.L. No. 97-35 § 2173 . This new standard, known as the Boren Amendment, required a state plan to

42 U.S.C.A. § 1396a(a)(13)(A) (West 1992).

The purpose of the Boren Amendment was “to give states greater flexibility in calculating reasonable costs and in containing the continuing escalation of those costs.” Folden, 981 F.2d at 1056 . The Third Circuit in West Virginia University Hospitals, Inc. v. Casey, 885 F.2d 11 (3d Cir.1989), aff'd on other grounds, 499 U.S. 83 , 111 S.Ct. 1138 , 113 L.Ed.2d 68 (1991), concluded that the Boren Amendment “authorizes states to develop their own medicaid reimbursement standards and method *1094 ologies for payment of hospital services, but subjects those standards and methodologies to three general federal requirements.” Id. at 22. First, states must take into account hospitals serving a disproportionate share of low-income patients. Id. at 22-23. Second, states must make findings that the rates are “reasonable and adequate” to meet the necessary costs of an efficiently operated hospital. Id. And third, states must assure Medicaid patients reasonable access to inpatient hospital care. Id. As the Third Circuit noted in West Virginia University Hospitals, these requirements are set forth in 42 C.F.R. §§ 447.250-447.280 . Id.

The plaintiffs in this case, eighteen hospitals outside of California that provided services to Medi-Cal patients, filed suit on March 28, 1995 for declaratory and injunc-tive relief. They allege that Belshe, the Director of the CDHS, is violating the Boren Amendment by failing to make the Amendment’s required findings for payments to out-of-state hospitals and by failing to make DSH payments to out-of-state hospitals serving a disproportionate share of low-income individuals. 1 Belshe moved for summary judgment, arguing that the Boren Amendment does not apply to out-of-state hospitals. On January 9,1997, the district court denied the motion, holding that the Amendment applies to out-of-state hospitals.

Soon after the district court issued its January 9, 1997 order, Congress amended the Medicaid Act to “eliminate the Boren Amendment and establish instead a notice and comment provision.” Exeter Memorial Hosp. Ass’n v. Belshe, 145 F.3d 1106, 1108 (9th Cir.1998) (citing Balanced Budget Act of 1997, Pub.L. No. 105-33, 111 Stat. 251, § 4711, codified at 42 U.S.C. § 1396a(a)(13)(A)). The new section became effective with respect to payments for services commencing October 1, 1997. See id. The new section continues to require that states take into account hospitals that serve a disproportionate number of low-income patients, but repeals the “findings” and “assurances” methodology enumerated in the Boren Amendment. Instead, the new section requires a “public process” for determining rates. 2

After the Boren Amendment was repealed, the district court held in a second order on February 4, 1998, that the CDHS’s method for reimbursing out-of-state hospitals did not satisfy the findings required by the Boren Amendment. In essence, the district court held that until the CDHS developed new rates for payment pursuant to the “public process” provisions of the .Balanced Budget Act of 1997, the CDHS had to comply with the Boren Amendment. The court also held that the Amendment required the CDHS *1095 to make DSH payments to out-of-state hospitals. Concluding that its determinations about the applicability of the Boren Amendment to out-of-state hospitals involved a “controlling question of law as to which there may be substantial ground for difference of opinion,” the district court certified the question for interlocutory appeal, which appeal this court authorized pursuant to 28 U.S.C. § 1292 (b). The district court then stayed the action pending our decision in this appeal.

DISCUSSION

A. Mootness and Eleventh Amendment Immunity

Belshe contends this appeal should be dismissed and the district court’s orders vacated because the repeal of the Boren Amendment renders any prospective relief moot. We disagree. A live controversy exists in this case, see Cook Inlet Treaty Tribes v. Shalala, 166 F.3d 986, 989 (9th Cir.1999), and we can grant effective relief. Cf. Calderon, v. Moore, 518 U.S. 149, 150 , 116 S.Ct. 2066 , 135 L.Ed.2d 453 (1996) (an appeal should be dismissed as moot “when, by virtue of an intervening event, a court of appeals cannot grant ‘any effectual relief whatever’ .... ” (citation omitted)).

After the Boren Amendment was repealed, HCFA advised its regional offices and the states participating in the Medicaid program that compliance with the new public process requirements of 42 U.S.C.A. § 1396a(a)(13)(A) (West Supp.1998) (the section that replaced the Boren Amendment) would be waived for payment methodologies that had been validly determined under the Boren Amendment. See December 10, 1997 Letter from HCFA to State Medicaid Director (“In other words, states are not required to subject their existing rates to a public process to the extent that those existing rates were validly determined in accordance with legal standards in effect prior to October 1, 1997.”). This letter from HCFA authorized states to continue to use payment methodologies approved under the Boren Amendment standard notwithstanding its repeal. Pursuant to this letter authority, CDHS continues to administer its MediCal program by using the Boren Amendment payment methodology. It refuses, however, to apply that methodology to its reimbursement of out-of-state hospitals for services they provide to Medi-Cal patients. The plaintiffs ask us to declare this exclusionary practice unlawful and to enjoin the CDHS from continuing it.

Because a live controversy exists and we can grant effective relief, we conclude this action is not mooted by the repeal of the Boren Amendment. Cf. Exeter Memorial Hosp. Ass’n v. Belshe, 145 F.3d 1106, 1108-09 (9th Cir.1998) (noting the repeal of the Boren Amendment after the district court’s decision, yet holding, without expressing concerns about mootness, that the CDHS violated the Boren Amendment when it implemented changes to its Medicaid plan without first obtaining federal approval).

Nor is the plaintiffs’ suit foreclosed by the Eleventh Amendment. Although the Eleventh Amendment precludes any action against state officers to recover past due payments, it does not preclude a suit against state officers for prospective relief from an ongoing violation of federal law. See Idaho v. Coeur d’Alene Tribe of Idaho, 521 U.S. 261, 288 , 117 S.Ct. 2028 , 138 L.Ed.2d 438 (1997) (O’Connor, J., concurring); Ex parte Young, 209 U.S. 123, 159-60 , 28 S.Ct. 441 , 52 L.Ed. 714 (1908). Here, the CDHS continues to administer its Medicaid program pursuant to the Boren Amendment, but denies reimbursement to out-of-state hospitals that provide services to Medi-Cal patients. In pursuing this course of action, the CDHS is committing an ongoing violation of federal law if the Boren Amendment applies to out-of-state hospitals. 3

*1096 B. Application of the Boren Amendment to Out-of-State Hospitals

For services rendered to Medi-Cal patients, California reimburses its in-state hospitals differently from the way it reimburses out-of-state hospitals. Belshe argues the Boren Amendment permits this because Congress intended to limit payments under Boren to in-state hospitals, and applying Boren’s requirements to out-of-state hospitals would impose a large, unintended administrative burden on the states. We reject Belshe’s legislative intent argument because it runs counter to the plain meaning of the Boren Amendment and the statute’s legislative history. We reject Belshe’s administrative burden argument because we find it unpersuasive.

1. Legislative Intent

a. Plain Meaning

Statutory interpretation begins with the language of the statute. See United States v. Ron Enters., Inc., 489 U.S. 235, 241 , 109 S.Ct. 1026 , 103 L.Ed.2d 290 (1989). When the plain meaning of a statutory provision is unambiguous, that meaning is controlling. Id. at 242 , 109 S.Ct. 1026 . To determine the plain meaning of a statutory provision, we examine not only the specific provision at issue, but also the structure of the statute as a whole, including its object and policy. See Green v. Commissioner, 707 F.2d 404, 405 (9th Cir.1983). If ambiguity exists, we may use legislative history as an aid to interpretation. See id.; Mt. Graham Red Squirrel v. Madigan, 954 F.2d 1441, 1453 (9th Cir.1992).

In setting forth the reimbursement requirements, the text of the Boren Amendment refers to “hospital services,” without limiting such services to those provided by in-state hospitals. 42 U.S.C.A. § 1396a(a)(13)(A) (West 1992). Belshe argues that Congress’s failure to refer to out-of-state hospitals in the Amendment points to Congress’s intent to exclude them. We disagree. In fact, it is the converse of this argument that is persuasive. Because the statute does not distinguish between in-state and out-of-state hospitals, the plain meaning of the statute is that Congress did not intend to differentiate between the two.

This interpretation is buttressed by the fact that elsewhere in the Medicaid statute (though not in the Boren Amendment) Congress creates distinctions for in-state institutions. For example, when a state plan includes medical assistance for services in an intermediate care facility for the mentally retarded, Congress requires periodic on-site inspections of each such facility “within the state.” 42 U.S.C.A. § 1396 (a)(31)(B) (West 1992).

Belshe refers to the definitions section of the Medicaid statute, 42 U.S.C. § 1396r-4(b)(l)(A), which sets forth the requirements for a hospital to be eligible for DSH payments. That section defines hospitals eligible for DSH payments by comparing them to the mean of “hospitals receiving medicaid payments in the State.” Belshe argues this language proves that the DSH payment requirement in the Boren Amendment applies only to in-state hospitals. This argument fails.

Section 1396r-4(b)(l)(A) provides that states administering their Medicaid programs are required to determine whether a hospital qualifies for DSH payments by referring to the mean number of Medicaid patients served by hospitals in their state. This language does not say that only hospitals within the state can qualify for DSH payments; instead, it uses in-state hospitals to calculate a benchmark for the number of Medicaid patients served to determine whether a hospital (in-state or out-of- *1097 state) qualifies for DSH payments. Hospitals serving a number of Medicaid patients “at least one standard deviation above the mean” qualify for DSH payments. 42 U.S.C. § 1396r-4(b)(l)(A). Thus, for example, a hospital in Arizona serving a number of Medicaid patients one standard deviation above the mean of hospitals serving Medicaid patients in California would meet this criterion for qualification, and could therefore seek DSH payments from California for treating Medi-Cal patients. Or, alternately, an Arizona hospital qualifying for DSH payments under the Arizona Medicaid program because of comparison with the mean of Arizona hospitals would similarly meet this criterion.

No court, other than the district court in this case, has directly interpreted the language of the Boren Amendment with regard to its applicability to out-of-state hospitals. Two courts have concluded by implication, however, that the Boren Amendment applies to out-of-state hospitals. In West Virginia University Hospitals, supra, 885 F.2d at 29, the Third, Circuit concluded that Pennsylvania’s reimbursement rate for a nearby West Virginia hospital that served many Pennsylvania Medicaid patients violated the requirements of the Boren Amendment. The court scrutinized the statutory language for its relevance to out-of-state hospitals:

Id.

In addition, a district court in this circuit has concluded by implication that the Boren Amendment applies to out-of-state hospitals. See Multicare Medical Center v. Washington, 768 F.Supp. 1349, 1401 (W.D.Wash.1991) (holding that Washington must make DSH payments to out-of-state border hospitals that serve Washington’s Medicaid recipients). These court decisions, while not directly on point, lend support to our conclusion that the Boren Amendment unambiguously applies to out-of-state hospitals.

b. Legislative History

Because the Boren Amendment is unambiguous, we need not examine its legislative history. See Green, 707 F.2d at 405 . Nevertheless, given the importance of the issue and the present view of the Secretary and HCFA, we shall examine the statute’s legislative history. See id. at 407 .

Congress passed the Boren Amendment “to give states greater flexibility in calculating reasonable costs and in containing the continuing escalation of those costs.” Folden, 981 F.2d at 1056 . The Senate Report comments that, under the Boren Amendment, “[s]tates would be free to establish rates on a statewide or other geographic basis, without reference to medicare principles of reimbursement.” S.Rep. No. 97-139, 97th Cong., 1st Sess. 478, reprinted in 1981 U.S. Code Cong. & Admin. News 744. As the district court correctly observed, this statement suggests that Congress was not assuming rates would be set under the Boren Amendment according to state boundaries.

The Senate Report also states that “[t]he flexibility given the States is not intended to encourage arbitrary reductions in payment that would adversely affect the quality of care.” Id. This statement demonstrates Congress’s underlying concern for 'maintaining quality health care, a goal which would be compromised if states could reduce their rates arbitrarily. Congress was also attentive to the broad purpose of the entire Medicaid program, which was to provide health care to low-income individuals. See West Virginia Univ. Hosp., 885 F.2d at 23 (explaining *1098 that the states’ discretion was limited by Congress’s desire to ensure that Medicaid recipients have access to services and that disproportionate share hospitals are not discouraged from providing care to Medicaid patients due to inadequate financial support).

As the district court wisely concluded, “[ijnasmuch as the Boren Amendment was a sophisticated attempt to fulfill [the goal of quality care] while at the same time encouraging efficiency, it makes little sense to remove out-of-state hospitals from that worthy rubric.”

Belshe asks us to defer to HCFA’s current interpretation of the Boren Amendment, which interpretation it propounded in an amicus curiae brief filed in the district court. In that brief, HCFA took the position that the Boren Amendment does not apply to out-of-state hospitals. We reject Belshe’s request. We may not defer to HCFA’s interpretation where Congress has unambiguously addressed the issue. See Chevron, U.S.A., Inc. v. N.R.D.C., Inc., 467 U.S. 837, 843 , 104 S.Ct. 2778 , 81 L.Ed.2d 694 (1984).

2. Administrative Burden

Belshe also argues that applying the Boren Amendment to out-of-state-hospitals would impose too high an administrative burden on the states. This argument relates to Congress’s intent in enacting, and then repealing, the Boren Amendment. Belshe contends that the repeal of the Boren Amendment and its replacement with a simpler public notice and comment requirement is evidence that Congress thought applying the Boren Amendment to out-of-state hospitals was too burdensome on the states. We reject this argument. Belshe fails to identify any statements by Congress raising the concerns she cites. Moreover, common sense dictates that, if Congress were concerned about the administrative burden imposed on the states by applying the Boren Amendment to out-of-state providers, instead of repealing the Amendment, it would simply have added the words “in-state” to the “hospital services” language of the Amendment. Congress’s actions, therefore, do not imply that the Amendment’s repeal was prompted by a concern for the burden of complying with the Anendment’s provisions for payments to out-of-state hospitals.

Nevertheless, Belshe argues Congress must have meant to exclude out-of-state hospitals from the Amendment because it would be impossible for a state to anticipate, and establish reimbursement rates for, all out-of-state hospitals where its Medicaid patients might receive care. Compounding the difficulty, Belshe argues, would be the necessity of determining whether the operational costs incurred by out-of-state facilities meet the “efficiently and economically operated facility” standard of the Boren Amendment.

The weakness in Belshe’s argument is that she presumes the Boren Amendment requires states to apply the same methodology and administrative requirements to out-of-state hospitals that „ states apply to in-state hospitals. This is not so. As the Third Circuit noted in West Virginia University Hospitals, “[w]e neither hold nor suggest that Pennsylvania must apply precisely the same methodology to ... out-of-state hospitals as it does for its in-state hospitals if there is a rational basis for departure.” 885 F.2d at 29 . The key is that “[t]he methodology applied ... be rational, not arbitrary or whimsical.” Id.

In the case of out-of-state hospitals providing only occasional emergency care, a state could develop a reasonable methodology for reimbursement different from its in-state provider methodology. Indeed, as the district court observed, some of the impracticalities Belshe cites would not necessarily apply to out-of-state hospitals. For example, many of the regulations Belshe cites as being too difficult to apply, such as uniform cost reporting and period audits, apply only to “participating providers,” which are hospitals enrolled in a state’s Medicaid program. See 42 C.F.R. § 447.253 (g). An out-of-state hospital *1099 might not be enrolled in such a program, although it could be. As the district court noted in reviewing the State of Georgia’s administration of its Medicaid program, some out-of-state hospitals are enrolled in Georgia’s Medicaid program and Georgia reimburses these hospitals at the same rates it uses to reimburse in-state, enrolled hospitals. With regard to non-enrolled out-of-state hospitals, however, Georgia reimburses them at rates consistent with the other state’s rates under the Medicaid program or at a specified percentage of allowable costs.

In sum, although the Boren Amendment has extensive reimbursement requirements, a factor that may well explain why Congress chose in 1997 to repeal it, the Amendment nonetheless permits states some flexibility in developing their reimbursement methodologies. We conclude, as did the Third Circuit in West Virginia University Hospitals, that a state need not use the same rate-setting scheme for nonparticipating out-of-state hospitals as it does for in-state hospitals. Although the administrative burden on states in reimbursing out-of-state providers under the Boren Amendment may still be significant, this burden does not provide evidence that Congress did not intend to apply the Amendment’s requirements to out-of-state hospitals.

CONCLUSION

Even though Congress repealed the Boren Amendment during the pendency of this action, the case is neither moot nor barred by the Eleventh Amendment. The CDHS has the option of complying with the Boren Amendment or with the public process provisions of the Balanced Budget Amendment of 1997. It does not have the option of failing to comply with either law. So long as it fails to comply with the Balanced Budget Amendment, it is bound by the Boren Amendment, and we hold that the Boren Amendment applies to all hospitals, including out-of-state hospitals. We reject Belshe’s contention that the administrative burden of applying the Amendment to out-of-state providers suggests that Congress intended otherwise.

AFFIRMED.

. The CDHS uses Boren Amendment standards in determining the methodology for reimbursing in-state hospitals, ninety percent of which are paid for inpatient services at a negotiated contract rate and some of which receive additional payments (“DSH payments”) for serving a disproportionate share of low-income patients. By contrast, Belshe admits that the CDHS pays out-of-state hospitals "at the average of the contract rates paid to California hospitals” and does not make any DSH payments to out-of-state hospitals.

. The new section of the statute requires that a state plan for medical assistance

42 U.S.C.A. § 1396a(a)(13)(A) (West Supp. 1998).

. Green v. Mansour, 474 U.S. 64, 106 S.Ct. 423 , 88 L.Ed.2d 371 (1985), on which the CDHS relies, is inapposite. There, the state brought its policy into compliance with a newly enacted federal law while the case was *1096 pending in the district court. Id. at 66 , 106 S.Ct. 423 . Here, although the Boren Amendment was repealed while this case was pending in the district court, the CDHS continues to operate under the Amendment and has not changed its policy of denying reimbursement to out-of-state hospitals that provide services to Medi-Cal patients; nor has it developed new rates for payment pursuant to the "public process” provisions of the Balanced Budget Act of 1997.