20 CFR 222.23: Relationship as surviving divorced spouse.

A claimant will be considered to be the surviving divorced spouse of a deceased employee if the conditions in either paragraph (a) or (b) of this section are met:

(a) Age or disability. The claimant applied for an annuity on the basis of age or disability, and the conditions set forth in § 222.22 are met.

(b) Child in care. The claimant applied for an annuity on the basis of having a child in care, and—

(1) His or her marriage to the employee has been terminated by a final divorce; and

(2) He or she is not married (if the claimant remarried after the divorce from the employee, the later marriage has been terminated by death, final divorce, or annulment); and

(3) He or she either—

(i) Was the natural parent of the employee's child; or

(ii) Had been married to the employee when either the employee or the claimant legally adopted the other's child or when they both legally adopted a child who was then under 18 years of age.