724.115—Next of kin.

The person or persons in the highest category of priority as determined by the following list (categories appear in descending order of priority): Surviving legal spouse; children (whether by current or prior marriage) age 18 years or older in descending precedence by age; father or mother, unless by court order custody has been vested in another (adoptive parent takes precedence over natural parent); siblings (whole or half) age 18 years or older in descending precedence by age; grandfather or grandmother; any other relative (precedence to be determined in accordance with the civil law of descent of the deceased former member's state of domicile at time of death).

CFR

724.115—Next of kin.