Commencement of enrollment period
All of the provisions of this section shall apply to individuals satisfying subsection (f), except that—
(1)#
in the case of an individual who satisfies subsection (f) by reason of entitlement to disability insurance benefits described in section 426(b) of this title , his initial enrollment period shall begin on the first day of the later of (A) April 1973 or (B) the third month before the 25th month of such entitlement, and shall reoccur with each continuous period of eligibility (as defined in section 1395r(d) of this title ) and upon attainment of age 65;
(2)#
(A) in the case of an individual who is entitled to monthly benefits under section 402 or 423 of this title on the first day of his initial enrollment period or becomes entitled to monthly benefits under section 402 of this title during the first 3 months of such period, his enrollment shall be deemed to have occurred in the third month of his initial enrollment period, and
(B) in the case of an individual who is not entitled to benefits under section 402 of this title on the first day of his initial enrollment period and does not become so entitled during the first 3 months of such period, his enrollment shall be deemed to have occurred in the month in which he files the application establishing his entitlement to hospital insurance benefits provided such filing occurs during the last 4 months of his initial enrollment period; and
(2)(A)#
in the case of an individual who is entitled to monthly benefits under section 402 or 423 of this title on the first day of his initial enrollment period or becomes entitled to monthly benefits under section 402 of this title during the first 3 months of such period, his enrollment shall be deemed to have occurred in the third month of his initial enrollment period, and
(2)(B)#
in the case of an individual who is not entitled to benefits under section 402 of this title on the first day of his initial enrollment period and does not become so entitled during the first 3 months of such period, his enrollment shall be deemed to have occurred in the month in which he files the application establishing his entitlement to hospital insurance benefits provided such filing occurs during the last 4 months of his initial enrollment period; and
(3)#
in the case of an individual who would otherwise satisfy subsection (f) but does not establish his entitlement to hospital insurance benefits until after the last day of his initial enrollment period (as defined in subsection (d) of this section), his enrollment shall be deemed to have occurred on the first day of the earlier of the then current or immediately succeeding general enrollment period (as defined in subsection (e) of this section).