entitlement of an individual to hospital insurance benefits for a month shall consist of entitlement to have payment made under, and subject to the limitations in, part A of subchapter XVIII on his behalf for inpatient hospital services, post-hospital extended care services, and home health services (as such terms are defined in part E of subchapter XVIII) furnished him in the United States (or outside the United States in the case of inpatient hospital services furnished under the conditions described in section 1395f(f) of this title ) during such month; except that (A) no such payment may be made for post-hospital extended care services furnished before January 1967, and (B) no such payment may be made for post-hospital extended care services unless the discharge from the hospital required to qualify such services for payment under part A of subchapter XVIII occurred (i) after June 30, 1966 , or on or after the first day of the month in which he attains age 65, whichever is later, or (ii) if he was entitled to hospital insurance benefits pursuant to subsection (b), at a time when he was so entitled; and