20 CFR §229.31

1. (a)A spouse who is married to the employee when the employee's application is filed can be included in the computation of the overall minimum rate beginning in the later of the month in which:
   1. (1)The employee first is eligible for an increase in his or her annuity under the overall minimum, as shown in § 229.22 of this part; or
   2. (2)The spouse first becomes eligible to be included under the overall minimum, as shown in § 229.30 of this part.
2. (b)A spouse who marries the employee after the employee application is filed can be included in the overall minimum computation in the month in which he or she becomes eligible, as shown in § 229.30 of this part, if the overall minimum rate is already payable in the previous month. If the railroad formula rate is payable in the month before the spouse becomes eligible, the spouse can be included in the overall minimum computation in the later of the month in which:
   1. (1)The employee first is eligible for an increase in his or her annuity rate under the overall minimum, as shown in § 229.22; or
   2. (2)The spouse annuity begins.