(a) The board of supervisors of any county subject to this article shall establish two defined contribution retirement plans authorized by Section 401 of the Internal Revenue Code of 1986. The terms of the plans shall be mutually agreed to by the employer and employee representatives of affected employees prior to adoption or amendment by the board of supervisors. The plans shall be known as General Plan F and Safety Plan F and are referred to collectively as plan F.
(b) Any general member described in subdivision (f) of Section 31510 shall participate in General Plan F, and any safety member described in subdivision (f) of Section 31510 shall participate in Safety Plan F, after commencement of his or her participation in the prior plan.
(c) The board, upon the advice of the actuary, shall determine the portion of the member contributions otherwise required under the prior plan that shall be credited to plan F in lieu of being credited to the other plan. In doing so, the board shall provide for the level of contributions to plan F that is the minimum amount sufficient to satisfy the purposes set forth in subdivision (b) of Section 31510.
(d) The right of the member to benefits derived from member contributions vests under plan F upon the commencement of participation in plan F.
(e) If a member or beneficiary becomes entitled to receive a benefit in the form of an annuity under the terms of the prior plan, the member’s account in plan F shall be converted to the same form of annuity as is payable to the member or beneficiary from the prior plan. The amount of the annuity payable under the prior plan, calculated prior to the application of this article (including the limitations set forth in Section 415 of the Internal Revenue Code of 1986), shall be reduced by the amount of the annuity generated under plan F as described in the preceding sentence. The amount payable from plan F shall be paid at the same time and in the same manner as the annuity payable from the prior plan and may be provided through an annuity contract purchased from an insurance company, at the discretion of the board. Notwithstanding the foregoing, if the member’s account in plan F does not exceed three thousand five hundred dollars ($3,500), it shall be paid to the member or beneficiary as a lump-sum payment, in lieu of the benefit otherwise payable under plan F.
(f) If a member or beneficiary becomes entitled to receive the member’s accumulated contributions and interest from the prior plan, the member or beneficiary shall receive the member’s account balance from plan F consisting of the member’s accumulated contributions and actual earnings at the same time and in the same manner.
(g) In applying the limitations set forth in Section 415 of the Internal Revenue Code of 1986, benefits or annual additions in qualified retirement plans maintained by an employer separate from the retirement system shall be reduced first. Any additional reduction shall be made to the benefits from plans within the retirement system other than plan F, and then lastly to the annual addition to plan F.
(h) Plan F shall be administered in accordance with subsection (a) of Section 401 of the Internal Revenue Code of 1986 and the Treasury Regulations issued thereunder. The plan shall state that it is intended to be a profit-sharing plan wherein contributions are determined without regard to current or accumulated profits.
(i) For the purpose of this article, the term “annuity” means the combined benefit provided by an annuity, as defined in Section 31457, and the pension, as defined in Section 31471.
(j) To the extent any county subject to this article terminates General Plan F or Safety Plan F, or both of them, with respect to any group of members and in accordance with their terms and adopts a replacement benefits program under Section 31899.4 for those members in lieu of that plan or plans, this section shall be inoperative in that county with respect to those members. In any event, the election made pursuant to subdivision (b) of Section 31510, the provisions of subdivisions (c), (d), (e), (f), and (h) of Section 31510, and the provisions of Section 31510.3 shall remain operative in that county.