Wash. Rev. Code § 2.14.110
If a member dies, the amount of the accumulated contributions standing to the member's credit at the time of the member's death, subject to the provisions of chapter 26.16 RCW, shall be paid to the member's estate, or such person or persons, trust, or organization as the member has nominated by written designation duly executed and filed with the administrative office of the courts. If there is no such designated person or persons still living at the time of the member's death, the member's accumulated contributions shall be paid to the member's surviving spouse as if in fact the spouse had been nominated by written designation or, if there is no such surviving spouse, then to the member's legal representatives.
RCW 2.14.110
Effective date-1988 c 109: See note following RCW 2.10.030.