20 CFR 229.43: When a divorced spouse can no longer be included in computing an annuity under the overall minimum.

A divorced spouse's inclusion in the computation of the overall minimum rate ends the earlier of:

(a) The month before the month in which the divorced spouse dies; or

(b) The month before the month the employee dies; or

(c) The month before the month in which the divorced spouse remarries; or

(d) The month before the month in which the divorced spouse becomes entitled to a retirement or disability benefit under the Social Security Act based upon a primary insurance amount which is equal to or exceeds the divorced spouse annuity before reduction for age.