(A)
For any month in which an annuitant is entitled both to an annuity under this subchapter as computed under paragraph (1) and to a disability insurance benefit under section 223 of the Social Security Act, the annuitant’s annuity for such month (as so computed) shall—
(i)
if such month occurs during a period referred to in paragraph (1)(A)(i), be reduced by 100 percent of the annuitant’s assumed disability insurance benefit for such month; or
(ii)
if such month occurs other than during a period referred to in paragraph (1)(A)(i), be reduced by 60 percent of the annuitant’s assumed disability insurance benefit for such month;
except that an annuity may not be reduced below zero by reason of this paragraph.