42 CFR §409.18

1. (a)Kidney transplants. Medicare pays for kidney transplantation surgery only if performed in a renal transplantation center approved under subpart U of part 405 of this chapter.
2. (b)Services in connection with kidney donations. Medicare pays for services related to the evaluation or preparation of a potential or actual donor, to the donation of the kidney, or to postoperative recovery services directly related to the kidney donation—
   1. (1)If the kidney is intended for an individual who has ESRD and is entitled to Medicare benefits or can be expected to become so entitled within a reasonable time; and
   2. (2)Regardless of whether the donor is entitled to Medicare.