Alaska Stat. § 39.35.850
(a) Each participant shall have the right to designate a beneficiary and shall have the right, at any time, to revoke the designation or to substitute another beneficiary, subject to the following limitation: if a married member elects a nonspouse beneficiary, the value of the benefit payable to the beneficiary may not exceed 50 percent of the member's portion of the account balance, and the member's spouse shall automatically be considered the beneficiary for the remaining 50 percent of the account balance, unless the spouse consents to the beneficiary designation in a writing that is notarized or witnessed by the administrator. If the spouse consents in this manner, a married member may designate a nonspouse beneficiary for the entire benefit or any portion the benefit as part of an available form of payment contained in this plan,
(c) If a member fails to designate a beneficiary, or if no designated beneficiary survives the member, the death benefit shall be paid