Code of Federal Regulations Title 20. Employees' Benefits § 20.404.374 Parent's relationship to the insured

(a) You are the mother or father of the insured and would be considered his or her parent under the laws of the State where the insured had a permanent home when he or she died;

(b) You are the adoptive parent of the insured and legally adopted him or her before the insured person became 16 years old;  or

(c) You are the stepparent of the insured and you married the insured's parent or adoptive parent before the insured became 16 years old. The marriage must be valid under the laws of the State where the insured had his or her permanent home when he or she died. See § 404.303 for a definition of permanent home.