Cal. Gov. Code § 31554
All officers and attaches of the superior court established within the county, except judges and participants in any other pension system, become members of the association on the first day of the calendar month after the board of supervisors adopts by four-fifths vote a resolution providing for their inclusion. Thereafter each person entering such employ becomes a member on the first day of the calendar month following his entrance into the service of the court.
In this section "officer or attache of the superior court" includes all commissioners, phonographic reporters who are paid salaries or per diems by the county and whose contributions are based upon such salaries or per diems, secretaries, stenographers, investigators, messengers, or other employees of the court.
Ca. Gov. Code § 31554