42 CFR 489.29: Special requirements concerning beneficiaries served by the Indian Health Service, Tribal health programs, and urban Indian organization health programs.

(a) Hospitals (as defined in sections 1861(e) and (f) of the Social Security Act) and critical access hospitals (as defined in section 1861(mm)(1) of the Social Security Act) that participate in the Medicare program and furnish inpatient hospital services must accept the payment methodology and no more than the rates of payment established under 42 CFR part 136, subpart D as payment in full for the following programs:

(1) A contract health service (CHS) program under 42 CFR part 136, subpart C, of the Indian Health Service (IHS);

(2) A CHS program under 42 CFR part 136, subpart C, carried out by an Indian Tribe or Tribal organization pursuant to the Indian Self-Determination and Education Assistance Act, as amended, Public Law 93-638, 25 U.S.C. 450 et seq.; and

(3) A program funded through a grant or contract by the IHS and operated by an urban Indian organization under which items and services are purchased for an eligible urban Indian (as those terms are defined in 25 U.S.C. 1603 (f) and (h)).

(b) Hospitals and critical access hospitals may not refuse service to an individual on the basis that the payment for such service is authorized under programs described in paragraph (a) of this section.