A hospital that provides services to Medicare patients is entitled to reimbursement under the Social Security Act ("Act"), 42 U.S.C. Sec. 1395, et seq. Underlying this case is a dispute between Georgetown University Hospital, along with several other hospitals in the District of Columbia ("Hospitals"), and the Secretary of Health and Human Services ("Secretary") regarding the Hospitals' entitlement to reimbursement for inpatient services under the Medicare Prospective Payment System ("PPS"). If a hospital disagrees with the Secretary's determination about the "amount of payment" due under PPS, the hospital may appeal first to the Provider Reimbursement Review Board ("Board" or "PRRB") and then to federal district court. 42 U.S.C. Secs. 1395oo (a), (f). In an earlier phase of this litigation, we affirmed a district court opinion holding that the Secretary miscalculated the amount of payment due the Hospitals and ordering the Secretary to recompute the Hospitals' PPS notice, to make the payments that had been wrongfully withheld, and to pay interest as required by the Act. See Georgetown University Hospital v. Bowen, 862 F.2d 323 (D.C.Cir.1988), aff'g 698 F. Supp. 290 (D.D.C.1987).

The current dispute involves the amount of interest that the Secretary owes the Hospitals on their underlying claims. The Act provides that when a hospital seeks judicial review, "the amount in controversy shall be subject to annual interest beginning on the first day of the first month beginning after the 180-day period [that is triggered by notice of the PPS rate notice] ... to be awarded by the reviewing court in favor of the prevailing party." Id. Sec. 1395oo (f)(2). The specific question in this case is: what is the "amount in controversy" on which interest accrues? Adopting the Hospitals' arguments, the district court held that the "amount in controversy"" is "the entire amount of disputed payments that the Secretary will withhold throughout the [hospital's fiscal] year, whether or not those payments have yet been withheld." Georgetown University Hospital v. Sullivan, Civ. Action No. 85-3650, Memorandum Opinion ("Mem. op.") at 3, 1989 WL 160627 (D.D.C. Nov. 7, 1989). The Secretary disagrees, arguing that "at any particular time after the 180-day period, plaintiffs are entitled only to interest on the amount of disputed payments that have been withheld up to that time." Id. Because we find that the Secretary's interpretation is the more reasonable interpretation of the ambiguous statutory language, we reverse.

When Congress amended the Act in 1974 to allow interest on the "amount in controversy," Medicare providers were reimbursed on a "reasonable cost" basis. 42 U.S.C. Sec. 1395f(b) (1983). At the end of the fiscal year, the provider filed with its fiscal intermediary a report representing the total costs for which the provider sought Medicare reimbursement. The fiscal intermediary then audited the report and issued a Notice of Program Reimbursement ("NPR"), detailing the allowable costs for which Medicare would reimburse the provider. If the provider was dissatisfied with the NPR, it could appeal to the PRRB and then to federal district court. Id. Secs. 1395oo (a), (f)(1). If the provider prevailed in court, it was entitled to interest on the "amount in controversy," with the interest calculated from 180 days after the issuance of the NPR. Id. Sec. 1395oo (f)(2).

In 1983, however, Congress partially replaced the cost-based reimbursement system with the PPS system.1 Under this system, providers are reimbursed based on prospectively determined rates that vary according to the type of treatment rendered. 42 U.S.C. Sec. 1395ww(d) (1991 Supp.). Before the beginning of its fiscal year, each hospital receives a PPS rate notice stating the amount of payment it will receive for each patient served during the year. In Washington Hospital Center v. Bowen, 795 F.2d 139 (D.C.Cir.1986), this court held that the PPS rate notice is a "final intermediary determination" subject to appeal under 42 U.S.C. Sec. 1395oo (a). Thus, a hospital may appeal the rates in the PPS rate notice as soon as the hospital receives the rate notice. But while the appeal is pending, the hospital continues to provide services and receive reimbursements from HHS at the rates set forth in the challenged notice. If the hospital eventually prevails on appeal, the Secretary must pay the difference between the reimbursement paid for each patient served while the inaccurate rate notice was in effect and the amount that would have been paid if the rate notice had been correct in the first instance.

If the hospital prevails, it is also entitled to interest under the litigation interest provision of the Act, 42 U.S.C. Sec. 1395oo (f)(2). That section provides that when a provider seeks judicial review, "the amount in controversy shall be subject to annual interest beginning on the first day of the first month beginning after the 180-day period [that is triggered by notice of the PPS rate notice] ... to be awarded by the reviewing court in favor of the prevailing party." 42 U.S.C. Sec. 1395oo (f)(2) (1983). Because the Hospitals receive the PPS rate notice just before the beginning of the fiscal year, both parties agree that interest generally begins to accrue in the middle of the fiscal year. The parties disagree, however, about the "amount in controversy" on which interest accrues. The Hospitals contend that it is the difference between the amount originally determined by the Secretary to be payable to the provider under PPS and the amount eventually determined by the court to be payable for the entire fiscal year. In other words, the amount in controversy is the amount that the Secretary wrongly withheld for all patients served during the fiscal year.2 The Secretary, on the other hand, views the "amount in controversy" as a fluctuating amount that increases as the year progresses and the Hospitals provide more services without receiving "full" payment. Thus the Secretary contends that at any particular time after the 180-day period has run, the Hospitals are entitled only to interest on the amount of disputed payments that have been withheld up to that time.

The district court ruled in the Hospitals' favor, finding that the plain language of the statute compels the conclusion that "there is one, and only one amount in controversy": the "amount in controversy as of the end of the [fiscal] year." Georgetown University Hospital, Mem. op. at 3-4. The Secretary appeals.

The Hospitals contend that the language of the litigation interest provision is clear and unambiguous: the "amount in controversy" is the amount that the Secretary wrongfully withheld for the entire fiscal year covered by the inaccurate PPS rate notice. We disagree. Although we recognize that the Hospitals set forth a reasonable interpretation of the "amount in controversy" language, for the reasons discussed below, we do not believe it is the only one. Furthermore, the Hospitals' interpretation creates an odd result not contemplated by Congress: the Secretary will have to pay interest on Medicare payments that he wrongfully withholds even before he wrongfully withholds them. Because there is no indication that Congress intended to waive the government's sovereign immunity to pay interest on principal before the principal is due, we decline to adopt the Hospitals' interpretation. Instead, we agree with the Secretary that the more reasonable interpretation of the litigation interest provision is that at any time after interest begins to accrue, the "amount in controversy" is the amount of disputed payments that the Secretary has withheld up to that point.3

The Hospitals argue, first, that the district court correctly concluded that "[t]he combination of the definite article 'the' with the singular 'amount' implies that there is one, and only one, amount in controversy." Georgetown, Mem. op. at 4. Therefore, they continue, the Secretary's assertion that the "amount in controversy" increases as the fiscal year progresses and the Hospitals provide more services without receiving full payment is inconsistent with the plain language of the statute. We are not persuaded. As the Secretary points out, 1 U.S.C. Sec. 1 states that "[i]n determining the meaning of any Act of Congress, unless the context indicates otherwise--words importing the singular include and apply to several persons, parties, and things." Consequently, the use of the singular noun does not preclude the possibility that there may be more than one amount that will be subject to interest.

Recognizing this, the Hospitals respond that 1 U.S.C. Sec. 1 is inapplicable because the context of the litigation interest provision at issue indicates that there is only one amount in controversy.4 In their view, the words "the amount in controversy" in the interest calculation section have the same meaning that they have in the jurisdictional section of the SSA.5 In both sections, they argue, the words mean "the amount of underpayment for the entire fiscal year in which the disputed PPS rate applies."6 Although it is true that this court in Washington Hospital, 795 F.2d at 143 n. 4, implicitly interpreted the jurisdictional requirement for individual appeals as the Hospitals suggest, that case does not compel us to adopt the Hospitals' interpretation of the interest provision.

The presumption that "identical words used in different parts of the same act are intended to have the same meaning ... is not rigid and readily yields whenever there is such variation in the connection in which the words are used as reasonably to warrant the conclusion that they were employed in different parts of the act with different intent." Atlantic Cleaners & Dyers, Inc. v. United States, 286 U.S. 427, 433, 52 S. Ct. 607, 609, 76 L. Ed. 1204 (1932). As the Secretary points out, the "amount in controversy" language serves a very different purpose in the jurisdictional section of the Act than it does in the interest section. In the former it fulfills the congressional determination that judicial review is warranted only where there is a significant amount of money at stake; in the latter, it fulfills the congressional determination that there should be some compensation for the delay inherent in judicial review. Consequently, the statutory language does not compel the conclusion that Congress obviously meant the "amount in controversy" language to be interpreted the same way in the jurisdictional and interest sections of the Act.7 Cf. Natural Resources Defense Council, Inc. v. Environmental Protection Agency, 673 F.2d 400, 403 n. 10 (D.C.Cir.) (the words "effluent limitation or other limitation" may have a different meaning in the section of the Clean Water Act dealing with judicial review of the Administrator's action than they do in the section dealing with citizen suits because of the "very different purposes served" by the two sections), cert. denied, 459 U.S. 879, 103 S. Ct. 175, 74 L. Ed. 2d 143 (1982); McCord v. Bailey, 636 F.2d 606, 617 n. 15 (D.C.Cir.1980) (although the words "any State or Territory" do not include the District of Columbia for purposes of defining whose officials will have liability under 42 U.S.C. Sec. 1983, they do include the District of Columbia for purposes of defining what conspiracies will be covered by 42 U.S.C. Sec. 1985(2)), cert. denied, 451 U.S. 983, 101 S. Ct. 2314, 68 L. Ed. 2d 839 (1981).

Furthermore, we are unwilling to adopt the Hospitals' interpretation of the "amount in controversy" language in the interest provision because it leads to an odd result not contemplated by Congress: interest accrues on principal before the principal is due. An example illustrates why this is true. Assume that a hospital receives a PPS rate notice in December describing the per-patient reimbursement schedule for various services that the hospital will provide during the fiscal year beginning January 1. Assume further that because the Secretary miscalculated the rates contained in the rate notice, the hospital will provide $10,000 worth of services each month but receive only $9,000 reimbursement from Medicare. If the hospital successfully appeals the rate notice, interest begins to accrue on July 1. See 42 U.S.C. Sec. 1395oo (f)(2). On that date, the Secretary will owe the hospital $6,000. Of course, if the hospital continues to provide services in the second half of the year as it did in the first half, the Secretary will owe the hospital an additional $1,000 each month, for a total of $12,000 at the end of the fiscal year.

Although in this example, the Secretary owes the hospital only $6,000 on July 1, the Hospitals contend that, beginning July 1, he must pay interest on the $12,000 that he will owe at the end of the fiscal year. This example illustrates, therefore, that acceptance of the Hospitals' argument would result in the Secretary having to pay interest on principal that is not yet due: he would have to pay interest on Medicare reimbursements that he wrongfully withholds before he wrongfully withholds them and, in fact, even before the hospital has earned them. Thus, the Hospitals' interpretation is inconsistent with the universally accepted business practice of calculating interest on outstanding principal. We agree with the Secretary that this is an odd result,8 and we decline to sanction it because there is no indication that it is what Congress intended. Cf. Public Citizen v. Department of Justice, 491 U.S. 440, 109 S. Ct. 2558, 105 L. Ed. 2d 377 (1989) (declining to adopt a literal interpretation of a statute that would compel an "odd result" when there was no other evidence that Congress intended that result).

When Congress enacted the interest provision in 1974, hospitals were reimbursed for in-patient services under the cost-based system. Under this system, the "final determination" of the amount of reimbursement due the provider is the NPR, 42 U.S.C. Sec. 1395oo (a)(1)(A)(i) (1983), which is not issued until after the close of the fiscal year, i.e., after the provider has rendered the services and the payment for those services is due. Because interest begins to accrue 180 days after the issuance of the NPR, id. Sec. 1395oo (f)(2), interest only accrues on outstanding payments for services that the provider has already rendered. Thus, as initially enacted, the interest provision comported with accepted business practice: interest only accrues on payments that are due, but that the Secretary has not paid.

When Congress adopted the PPS system, it did not amend the interest provision. The Hospitals contend that because the Secretary had previously interpreted the "amount in controversy" language to mean "the amount in controversy for the entire fiscal year" for cost-based system appeals, the failure to modify the interest provision indicates that Congress intended the phrase to have the same meaning for PPS appeals, even though this significantly increases the amount of interest the Secretary must pay when he wrongfully withholds Medicare payments. We are not persuaded. The Supreme Court has warned that "[i]t is at best treacherous to find in congressional silence alone the adoption of a controlling rule of law." Girouard v. United States, 328 U.S. 61, 69, 66 S. Ct. 826, 829, 90 L. Ed. 1084 (1946); see also Chisholm v. FCC, 538 F.2d 349, 361-65 (D.C.Cir.), cert. denied, 429 U.S. 890, 97 S. Ct. 247, 50 L. Ed. 2d 173 (1976). Our review of the legislative history leaves us with the distinct impression that Congress did not even contemplate, much less intend, that the PPS amendments would authorize the payment of interest on wrongfully withheld Medicare payments before those payments are due.9 Unlike the Hospitals, therefore, we are unable to conclude that Congress' failure to amend the litigation interest provision indicates a congressional intent to award interest on Medicare payments that the Secretary wrongfully withholds even before he wrongfully withholds them.

Moreover, in the absence of any indication that Congress intended the waiver of sovereign immunity embodied in the litigation interest provision to be so broadly construed, we are unwilling to adopt the Hospitals' interpretation of the ambiguous "amount in controversy" language. Cf. McMahon v. United States, 342 U.S. 25, 26, 72 S. Ct. 17, 18, 96 L. Ed. 26 (1951) ("statutes which waive immunity of the United States from suit are to be construed strictly in favor of the sovereign"); see also Library of Congress v. Shaw, 478 U.S. 310, 318, 106 S. Ct. 2957, 2963, 92 L. Ed. 2d 250 (1986) (same). Instead, we agree with the Secretary that the language should be construed in favor of the government and in a way that makes the accrual of interest on disputed Medicare payments in PPS appeals consistent with established business practice and with the accrual of interest in appeals under the cost-based Medicare reimbursement system.

For the reasons discussed above, we hold that when a provider successfully challenges a PPS rate notice, the "amount in controversy" on which interest accrues is, at any particular time, the amount of disputed payments that the Secretary has wrongfully withheld up to that time. We therefore reverse the contrary district court holding and remand for proceedings consistent with this opinion.

It is so ordered.