10 U.S.C. § 1085: Medical and dental care from another executive department: reimbursement

If a member or former member of a uniformed service under the jurisdiction of one executive department (or a dependent of such a member or former member) receives inpatient medical or dental care in a facility under the jurisdiction of another executive department, the appropriation for maintaining and operating the facility furnishing the care shall be reimbursed at rates established by the President to reflect the average cost of providing the care.