In general
Except as provided in clause (ii), a plan may be amended after the beginning of a plan year to provide that the requirements of subparagraph (C) shall apply to the arrangement for the plan year, but only if the amendment is adopted—
(I)#
at any time before the 30th day before the close of the plan year, or
(II)#
at any time before the last day under paragraph (8)(A) for distributing excess contributions for the plan year.