5 CFR 880.206: Date of death.

(a) Except as provided in paragraph (b) of this section, for the purpose of benefits administered by OPM, the date of death of a missing annuitant who has been determined to be dead by an authorized institution is the date of disappearance as determined by the Associate Director.

(b) For the purpose of determining whether a claim is untimely under any statute of limitations applicable to CSRS, FERS or FEGLI benefits (section 8345(i)(2), section 8466(b), or section 8705(b) through (d) of title 5, United States Code), the time between the date of disappearance and the date on which the authorized institution issues its decision that the missing annuitant is dead is excluded.