169.326.  Optional plans for payment of benefits — limitations — waiver. — 1.  Until the first payment on account of any benefit becomes due, any retirant may elect, by delivering written notice duly acknowledged to the board of trustees, to receive the actuarial equivalent of the person's annual service retirement allowance or disability retirement allowance in the form of one of the options set forth below.  No optional selection shall become effective in case a retirant dies within thirty days after retirement or within thirty days after filing such election; in such event the retirant shall be considered as an active member at the time of the retirant's death.

Option 1.  

Upon the person's death, the person's retirement allowance shall be continued throughout the life of and paid to such person as the person shall nominate by written designation duly acknowledged and delivered to the board of trustees at or prior to the time of the person's retirement, provided that in the event the person's designated beneficiary predeceases the person, then the person's retirement allowance shall be adjusted at that time to the amount determined pursuant to subsection 1 of section 169.324 at the time of the retirement of the person, or

Option 2.  

Upon the person's death, one-half of the person's retirement allowance shall be continued throughout the life of and paid to such person as the person shall nominate by written designation duly acknowledged and filed with the board of trustees at or prior to the time of the person's retirement, provided that in the event the person's designated beneficiary predeceases the person, then the person's retirement allowance shall be adjusted at that time to the amount determined under subsection 1 of section 169.324 at the time of the person's retirement, or

Option 3.  

Upon the person's death, no benefits shall be paid to any beneficiary or estate of the retired member.  This optional benefit is actuarially increased over the benefit formula providing for benefits at death.

  2.  If the death of any member who has not elected an option occurs before the person has received total benefits at least as large as accumulated contributions at retirement, the difference shall be paid in one lump sum to the person's designated beneficiary, if living, otherwise to the estate of the retired member.

  3.  If an active member dies, or if an inactive member dies before retirement but after becoming eligible to retire and commence receiving retirement benefits, and a dependent of the member (spouse, dependent child under age nineteen or dependent parent) is designated as primary beneficiary to receive the member's accumulated contributions, the beneficiary may, in lieu thereof, at the beneficiary's option, request that the benefit be paid under option 1 in subsection 1 of this section as if the member had retired as of the date of death and designated such beneficiary as the option 1 beneficiary; except that if the beneficiary is a dependent child, the option 1 benefit shall be payable only until the child attains age nineteen and not throughout the life of such child.  If the designated beneficiary elects the option 1 benefit and if the member was an active member at the time of death, such benefit shall be calculated as if the deceased member had, at the time of death, at least ten years' creditable service.  If more than one dependent is designated as beneficiary, the benefit shall be shared equally as determined by the actuary.  The determination of the board of trustees as to whether a person is a dependent for the purpose of this subsection shall be final.

  4.  Notwithstanding anything contained in sections 169.270 to 169.400 to the contrary, the payment of the annual service retirement allowance, or the actuarial equivalent of the annual service retirement allowance payable under any option prescribed in this section, shall at all times comply with the distribution rules of Section 401(a)(9) of the Internal Revenue Code of 1986, as amended, and the regulations thereunder, the terms of which are specifically incorporated herein by reference.

  5.  No person who would otherwise qualify as a dependent or beneficiary shall be eligible for, or entitled to, any benefits when such person is the principal or an accomplice in willfully bringing about the death of a member, retirant, or another dependent or beneficiary whose death would otherwise have resulted in payment of a benefit or a benefit increase to such person.  The determination of the board of trustees that such person willfully brought about such death shall be made from a preponderance of the evidence presented and shall not be controlled by any contrary finding by any other forum, whether considered under the same or another degree of proof.

  6.  Any retirant or dependent or beneficiary who is entitled to or receiving benefits from the retirement system may, on a form prescribed by the board of trustees and filed with the board, irrevocably waive all or any portion of his or her retirement allowance or survivor benefit or any other benefit payable hereunder.  Such waiver shall apply only to benefits that are payable on or after the date the waiver is filed.  If a retirant files an irrevocable waiver in accordance with this subsection, the waiver shall apply only with respect to the retirant and shall not affect the rights of any dependents or other beneficiaries upon the retirant's death.  If a dependent or beneficiary files an irrevocable waiver in accordance with this subsection, any benefits payable hereunder as a result of the death of a member or retirant shall be paid as if such dependent or beneficiary did not exist.