5 C.F.R. § 1651.9 Participant's next of kin.
Title 5 - Administrative Personnel
If the account is to be paid to the participant's next of kin under §1651.2(a)(6), the next of kin of the participant will be determined in accordance with the state law of the participant's domicile at the time of death.
Title 5: Administrative Personnel
PART 1651—DEATH BENEFITS
§ 1651.9 Participant's next of kin.