42 C.F.R. § 415.170 : Public Health — CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES — MEDICARE PROGRAM — SERVICES FURNISHED BY PHYSICIANS IN PROVIDERS, SUPERVISING PHYSICIANS IN TEACHING SETTINGS, AND RESIDENTS IN CERTAIN SETTINGS — PHYSICIAN SERVICES IN TEACHING SETTINGS — Conditions for payment on a fee schedule basis for physician services in a teaching setting

Services meeting the conditions for payment in § 415.102(a) furnished in teaching settings are payable under the physician fee schedule if-

(a) The services are personally furnished by a physician who is not a resident; or
(b) The services are furnished by a resident in the presence of a teaching physician except as provided in §415.172 (concerning physician fee schedule payment for services of teaching physicians), §415.174 (concerning an exception for services furnished in hospital outpatient and certain other ambulatory settings), §415.176 (concerning renal dialysis services), and §415.184 (concerning psychiatric services), as applicable.

42 C.F.R. §415.170