(a) Beneficiary designation. A member may from time to time designate a beneficiary in writing, or change such
designation of, any person or persons, contingently or successively, to whom the trustee
shall pay the remainder of his benefit in the event of his death. The board shall
prescribe the form for the written designation of beneficiary and, upon the member's
filing the form with the board, it effectively shall revoke all designations filed
prior to that date by the same member. This subsection (a) shall not supersede the
provisions of subsection (b) of section 16-169
(b) No beneficiary designation. If a member fails to name a beneficiary in accordance with the preceding subsection,
or if the beneficiary named by a member predeceases him or her, or dies before complete
distribution of the member's benefit, then the board shall pay the member's remaining
benefit, if any, to the member's estate.