Wash. Rev. Code § 41.37.170
(1) Upon retirement for service as prescribed in RCW 41.37.210 or retirement for disability under RCW 41.37.230, a member shall elect to have the retirement allowance paid pursuant to one of the following options, calculated so as to be actuarially equivalent to each other.
(2)
(c) If a copy of a dissolution order designating a survivor beneficiary under RCW 41.50.790 has been filed with the department at least thirty days prior to a member's retirement:
(3) The department shall adopt rules that allow a member additional actuarially equivalent survivor benefit options, and shall include, but are not limited to:
(a)
(4) The department shall adopt rules to permit:
[ 2020 c 161 s 5; 2019 c 102 s 6; 2004 c 242 s 23.]