The annuity of a spouse or divorced spouse is recomputed to use the employee's recomputed tier I PIA and tier II rate, if the recomputation results in a lump-sum payment of more than $5 or an increase in the spouse or divorced spouse annuity rate of more than $1 a month. The spouse or divorced spouse annuity rate is recomputed beginning with the same date the employee's annuity rate is recomputed.
20 C.F.R. § 226.92