Shalala

The Secretary of Health and Human Services (“Secretary”), appeals the district court’s summary judgment in favor of plaintiff hospitals. The district court overturned the Secretary’s interpretation of a Medicare reimbursement provision, deciding that Congress intended to count all days spent in hospitals by low-income patients, whether or not paid by Medicaid, in reimbursing increased costs to hospitals serving a disproportionately high number of low-income patients. We have jurisdiction under 28 U.S.C. § 1291 , and we affirm.

I

Medicare is a health insurance program that pays for covered medical care primarily to aged and disabled persons. 42 U.S.C. §§ 1395 et seq. Medicaid is a cooperative federal-state- program that provides health care to indigent persons who are aged, blind, or disabled, or members of families with dependent children. 42 U.S.C. §§ 1396 et seq. The program is jointly financed by the federal and state governments, and administered by the states according to the federal guidelines. Id.; 42 C.F.R. § 430.0 . States are required to cover specific medical services, and at their option may cover additional services. 42 U.S.C. § 1396d(a). Medicaid also specifies…