Neb. Rev. Stat. § 42-1106: Neb. Rev. Stat. § 42-1106

If the alternate payee dies prior to receiving any payment of his or her interest in the member's benefit under a qualified domestic relations order, such interest reverts to the member. If the alternate payee dies after commencement of payments of his or her interest, then the alternate payee's beneficiary is entitled to the balance of the payee's interest under the payment option provided by the order or selected by the payee, except a joint and survivor annuity option with the alternate payee and alternate payee's spouse.