42 CFR § 409.16
Other diagnostic or therapeutic services
June 11, 2020
Diagnostic or therapeutic services other than those provided for in §§409.12, 409.13, and 409.14 are considered as inpatient hospital or inpatient CAH services if—
(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.
[48 FR 12541, Mar. 25, 1983, as amended at 58 FR 30666, May 26, 1993]