20 CFR §216.63

1. (a)A widow(er) of an employee who completed 10 years of railroad service and had a current connection with the railroad industry at death is eligible for an annuity as a remarried widow(er) if he or she:
   1. (1)Remarried either:
      1. (i)After having attained age 60 (after age 50 if disabled); or
      2. (ii)Before age 60 but the marriage terminated;
   2. (2)Is not entitled to an old-age benefit under the Social Security Act that is equal to or higher than the full amount of the remarried widow(er)'s annuity before any reduction for age; and
   3. (3)Has attained retirement age;
   4. (4)Is at least 50 but less than 60 years of age and is disabled as defined in part 220 of this chapter before the end of the period described in § 216.68 (this results in a reduced annuity);
   5. (5)Has not attained retirement age but has in his or her care a child who either is under age 16 or is disabled, and who is entitled to an annuity under subpart H of this part; or
   6. (6)Is at least age 60 but has not attained retirement age. (In this case, the annuity is reduced for each month the remarried widow(er) is under retirement age when the annuity begins.)
2. (b)An individual entitled to a widow(er)'s annuity may be entitled to an annuity as a remarried widow(er) if he or she:
   1. (1)Remarries after having attained age 60 (after age 50 if he or she has been determined to be disabled prior to his or her remarriage) and is not a surviving divorced spouse; or
   2. (2)Is entitled to an annuity based upon having a child of the employee in his or her care and marries an individual entitled to a retirement, disability, widow(er)'s, mother's, father's, parent's, or disabled child's benefit under the Railroad Retirement Act or Social Security Act.