Medicare pays the beneficiary for the following services, if covered, in the specified circumstances:
(a) Emergency inpatient and outpatient services furnished by a nonparticipating U.S. hospital that has not elected to claim payment in accordance with subpart G of this part.
(b) Certain medical and other health services covered under Medicare Part B and furnished by a nonparticipating U.S. hospital, if the hospital does not receive assigned payment as a supplier under § 424.55.
(c) Emergency or nonemergency services furnished by a foreign hospital if the hospital does not have in effect an election to claim payment in accordance with subpart H of this part.
(d) Physician and ambulance services furnished outside the United States.
(e) Services furnished by a supplier if the claim has not been assigned to the supplier.