Wash. Rev. Code § 41.44.220
A member may elect to receive in lieu of the retirement allowance provided for in RCW 41.44.150, its actuarial equivalent in the form of a lesser retirement allowance, payable in accordance with the terms and conditions of one of the options set forth below in this section. Election of any option must be made by written application filed with the board at least thirty days in advance of retirement, or may be made by any member after he or she has attained the minimum requirements for his or her service retirement as required by RCW 41.44.140, and shall not be effective unless approved by the board prior to retirement of the member.
Option A. The lesser retirement allowance shall be payable to the member throughout his or her life: PROVIDED, That if he or she die before he or she receives in annuity payments referred to in paragraph (a) of subsection (1) of RCW 41.44.150 a total amount equal to the amount of his or her accumulated contributions as it was at date of his or her retirement, the balance of such accumulated contributions shall be paid in one sum to his or her estate or to such person having an insurable interest in his or her life as he or she shall nominate by written designation duly executed and filed with the board.
Option B. The lesser retirement allowance shall be payable to the member throughout life, and after death of the member, one-half of the lesser retirement allowance shall be continued throughout the life of and paid to the wife or husband of this member.
Option C. The lesser retirement allowance shall be payable to the member throughout life, and after death of the member it shall be continued throughout the life of and paid to the wife or husband of the member.
A member may apply for some other benefit or benefits and the board may grant such application provided such other benefit or benefits, together with the reduced retirement allowance, shall be certified by the actuary to be of equivalent value to his or her retirement allowance.
The surviving spouse may elect to receive a cash refund of the member's accumulated contributions in lieu of the monthly benefit under either Option B or Option C.
RCW 41.44.220