(a) When adjudicators initiate reopenings. When any determination or decision is reopened and revised as provided in Sec. 423.1980:
(1) The Part D plan sponsor, IRE, ALJ, or the MAC must mail its revised determination or decision to the enrollee at his or her last known address.
(2) The IRE, ALJ, or the MAC must mail its revised determination or decision to the Part D plan sponsor.
(3) An adverse revised determination or decision must state the rationale and basis for the reopening and revision and any right to appeal.
(b) Reopenings initiated at the request of an enrollee or a Part D plan sponsor. (1) The Part D plan sponsor, IRE, ALJ, or the MAC must mail its revised determination or decision to the enrollee at his or her last known address.
(1) The Part D plan sponsor, IRE, ALJ, or the MAC must mail its revised determination or decision to the enrollee at his or her last known address.
(2) The IRE, ALJ, or the MAC must mail its revised determination or decision to the Part D plan sponsor.
(3) An adverse revised determination or decision must state the rationale and basis for the reopening and revision and any right to appeal.