(a) Basic rule. Except as specified in paragraph (b) of this section, Medicare does not pay for services furnished outside the United States. For purposes of this paragraph (a), the following rules apply:
(1) The United States includes the 50 States, the District of Columbia, Puerto Rico, the Virgin Islands, Guam, American Samoa, The Northern Mariana Islands, and for purposes of services rendered on board ship, the territorial waters adjoining the land areas of the United States.
(2) Services furnished on board ship are considered to have been furnished in United States territorial waters if they were furnished while the ship was in a port of one of the jurisdictions listed in paragraph (a)(1) of this section, or within 6 hours before arrival at, or 6 hours after departure from, such a port.
(3) A hospital that is not physically situated in one of the jurisdictions listed in paragraph (a)(1) of this section is considered to be outside the United States, even if it is owned or operated by the United States Government.
(b) Exception. Under the circumstances specified in subpart H of part 424 of this chapter, payment may be made for covered inpatient services furnished in a foreign hospital and, on the basis of an itemized bill, for covered physicians' services and ambulance service furnished in connection with those inpatient services, but only for the period during which the inpatient hospital services are furnished.