Cal. Gov. Code § 22826

For purposes of this part, service credit shall be determined according to the rules of the retirement system provided by the employer in which the employee participates. In the case of elected officials not eligible for participation in a retirement system, service credit shall be determined according to the number of years in office. In the elected official’s final year of office, a completed term of office shall be sufficient to earn one year of service credit for that final year of office.