A divorced spouse annuity ends with the earliest of the last day of the month before the month in which the—
Divorced spouse dies;
Employee's entitlement to an annuity ends;
Divorced spouse marries;
Employee dies; or
Divorced spouse becomes entitled to a retirement or disability insurance benefit under the Social Security Act based on a primary insurance amount which equals or exceeds the amount of the full divorced spouse annuity before reduction for age.