(a) When evidence of the employee's death is required. Evidence to prove the employee's death is always required for payment of any type of survivor annuity or lump-sum payment based on the deceased employee's record. See parts 216 and 234 for types of survivor payments.
(b) When evidence to prove death of other persons is required. Evidence to prove the death of persons other than the empoyee is required when--
(1) A claimant, who is eligible for survivor benefits, dies after the employee;
(2) A residual lump sum (see part 234 of this chapter) is payable and a person whom the employee named to receive all or part of this payment dies before the employee, or such person dies after the employee but before receiving his or her share of the benefit; or
(3) There is reasonable doubt of the death of--
(i) Any person who, if alive, has priority over the applicant;
(ii) Any spouse whose death is alleged to have ended a previous marriage, if a later marriage in question cannot be presumed valid under state law; or
(iii) Any person the termination of whose entitlement would increase payments to other entitled persons.