Gov. Code, § 31498

(a) Any person employed subsequent to the effective date of this article who would otherwise qualify as a member shall not become a member until he or she certifies to the board his or her election to be covered by the retirement plan established by this article or to be covered by the retirement provisions and benefits otherwise available to members on the date preceding the effective date of this article. As a condition of continued employment, the certification shall be made within 60 days of employment. The employer shall make available to the person a disclosure of the elements of each of the available retirement plans prior to accepting his or her election.

(b) If the person does not elect to be covered by either Retirement Plan 2 or Retirement Plan 3 within 60 days of employment, the person shall automatically be covered by Retirement Plan 2 and no certification shall be required.