Wash. Rev. Code § 41.28.170
A member may elect to receive, in lieu of the retirement allowance provided for in RCW 41.28.130, 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 of administration at least thirty days in advance of retirement as provided in RCW 41.28.120, 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 receive in annuity payments referred to in RCW 41.28.130(1)(a), a total amount equal to the amount of his or her accumulated contributions as it was at the 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 a member throughout his or her life: PROVIDED, That if he or she die before he or she receive in annuity payments referred to in RCW 41.28.130(1)(a), a total amount equal to the amount of his or her accumulated contributions as it was at the date of his or her retirement, the said annuity payments resulting from his or her accumulated contributions shall be continued and paid to his or her estate or 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 until the total amount of annuity payments shall equal the amount of his or her accumulated contributions as it was at the date of his or her retirement.
Option C. The member shall elect a "guaranteed period" of any number of years. If he or she dies before the lesser retirement allowance has been paid to him or her for the number of years elected by him or her as the "guaranteed period", the lesser retirement allowance shall be continued to the end of the "guaranteed period", and during such continuation shall be paid 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 D. The lesser retirement allowance shall be payable to the member throughout life, and after the 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 the member.
Option E. 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.
RCW 41.28.170