Supreme Court Decision Syllabus (scotus)

 The Indian Self-Determination and Education Assistance Act, 25 U. S. C. §5301 et seq., enables an Indian tribe to enter into a “self-determination contract” with the Indian Health Service to assume responsibility for administering the healthcare programs that IHS would otherwise operate for the tribe. §5321(a)(1). When IHS administers such programs itself, it funds its operations through congressional appropriations and third-party insurance payments. Healthcare programs administered by a tribe under a self-determination contract have a parallel funding structure. First, IHS must provide to the tribe the Secretarial amount, which “shall not be less” than the congressionally appropriated amount that IHS would have used to operate such programs absent the self-determination contract. §5325(a)(1). Second, like IHS when it runs the healthcare programs, a contracting tribe can collect revenue from third-party payers like Medicare, Medicaid, and private insurers. See 42 U. S. C. §§1395qq(a), 1396j(a); 25 U. S. C.