Cal. Gov. Code § 20710
Subject to rules prescribed by the board, any member or any employer, other than the state, on behalf of any group of miscellaneous members, any group of members designated by the employer as management employees, or any members, may elect to make contributions in excess of the member's normal contributions, for the purpose of providing additional benefits. The exercise of this privilege by a member does not require his or her employer to make any additional contributions. An election by an employer to make the additional contributions does not require any member to make additional contributions and the additional contributions shall continue in effect for the period as shall be specified in the election filed with the board and a member shall acquire no right by reason of his or her employment while the election is in effect to a continuation of those contributions beyond the period specified in the election. Upon application, the board shall furnish information concerning the nature and amount of additional benefits to be obtained from additional contributions. The board may by rule provide for refund of accumulated additional contributions to a member. However, a refund of additional contributions may be made to a member if an employer had made additional contributions on his or her behalf only as a part of a refund of accumulated contributions in accordance with this part.
Wherever in this part provision is made with respect to additional or accumulated additional contributions of a member the term shall include contributions made by an employer pursuant to this article.
The board shall provide for additional employer contributions to be credited at least monthly to the individual account of the member on behalf of whom the contribution is made.
Ca. Gov. Code § 20710