California Code, Government Code - GOV § 31663.26

(a) Notwithstanding Section 31663.25, a safety member who has reached the applicable compulsory age of retirement, if any, or a safety member who is a full-time employee, has completed 10 years of service, has reached the age of 50, and has no service break which exceeds 12 months, or a safety member who has completed 20 years of service regardless of age, may be retired upon filing with the board a written application setting forth the date upon which the member desires the member's retirement to become effective.  The effective retirement date shall not be either of the following:

(b) This section shall not be operative in any county until such time as the board of supervisors shall, by ordinance, make this section applicable in the county.

(c) This section shall not apply to a member who is subject to the provisions of the California Public Employees' Pension Reform Act of 2013 for all or any portion of their membership in the county retirement system.