29 CFR § 4022.94 - What are the PBGC's rules on designating a person to get benefits the PBGC may owe me at the time of my death?
(c) If your designee dies before you -
(1) In general. If the person(s) you designate with us dies before you or at the same time as you, we will treat you as not having designated anyone with us (unless you named an alternate designee who survives you). Therefore, you should keep your designation with us current.
(2) Simultaneous deaths. If you and a person you designated die as a result of the same event, we will treat you and that person as having died at the same time, provided you and that person die within 30 days of each other.
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