First, to the beneficiary or beneficiaries designated by the employee in a signed and witnessed writing received before death in the employing office or, if insured because of receipt of annuity or of benefits under subchapter I of chapter 81 of this title as provided by section 8706(b) of this title, in the Office of Personnel Management. For this purpose, a designation, change, or cancellation of beneficiary in a will or other document not so executed and filed has no force or effect.
Second, if there is no designated beneficiary, to the widow or widower of the employee.
Third, if none of the above, to the child or children of the employee and descendants of deceased children by representation.
Fourth, if none of the above, to the parents of the employee or the survivor of them.
Fifth, if none of the above, to the duly appointed executor or administrator of the estate of the employee.