Code of Federal Regulations Title 42. Public Health § 42.409.16 Other diagnostic or therapeutic services

(a) They are furnished by the hospital or CAH, or by others under arrangements made by the hospital or CAH;

(b) Billing for those services is through the hospital or CAH;  and

(c) The services are of a kind ordinarily furnished to inpatients either by the hospital or CAH or under arrangements made by the hospital or CAH.