The Medicare Program defines physicians to include the following:

Doctors of dental surgery or dental medicine
; Doctors of medicine and doctors of osteopathy
; Doctors of optometry
; or Doctors of podiatry or surgical chiropody.

In addition, the Medicare physician must be legally authorized to practice by a State in which he or she performs this function. The services performed by a physician within these definitions are subject to any limitations imposed by the State on the scope of practice. The issuance by a State for a license to practice medicine constitutes legal authorization. A temporary State license also constitutes legal authorization to practice medicine. If State law authorizes local political subdivisions to establish higher standards for medical practitioners than those set by the State licensing board, the local standards are used in determining whether the physician has legal authorization. If the State licensing law limits the scope of practice of a particular type of medical practitioner, only the services within these limitations are covered


The Medicare Program defines a practitioner as any of the following to the extent that an individual is legally authorized to practice by the State and otherwise meets Medicare requirements: Anesthesiologist assistant (AA); Certified nurse midwife (CNM); Clinical nurse specialist (CNS); Certified registered nurse anesthetist (CRNA); Clinical psychologist (CP); Clinical social worker (CSW); Nurse practitioner (NP); Physician assistant (PA); or Registered dietician or nutrition professional.

Interns and Residents
Interns and residents include individuals who: Participate in approved Graduate Medical Education (GME) programs; or Are not in approved GME programs, but are authorized to practice only in a hospital setting (e.g., have temporary or restricted licenses or are unlicensed graduates of foreign medical schools). Also included in this definition are interns, residents, and fellows in GME programs recognized as approved for purposes of direct GME and Indirect Medical Education payments made by Fiscal Intermediaries (FI) or A/B Medicare Administrative Contractors (MAC). Receiving staff or faculty appointments, participating in fellowships, or whether a hospital includes physicians in its full-time equivalency count of residents does not by itself alter the status of “resident.”

Teaching Physicians
Teaching physicians are physicians (other than interns or residents) who involve residents in the care of their patients. Generally, teaching physicians must be present during all critical or key portions of the procedure and immediately available to furnish services during the entire service in order for the service to be payable under the Medicare Physician Fee Schedule (MPFS).