California Code, Government Code - GOV § 19141

(a) This section applies only to an employee in an exempt position who previously had permanent status in the civil service.  As used in this section, “former position” is defined as in Section 18522, or, if the appointing power to which reinstatement is to be made and the employee agree, a vacant position in any department, commission, or state agency for which he or she is qualified and which is at substantially the same level as the employee's former position.

(b) An employee who vacates a civil service position to accept an appointment to an exempt position shall be reinstated to his or her former position at the termination of the exempt appointment, provided both of the following conditions are met:

(c) An employee who vacates his or her civil service position to accept an assignment as a member, inmate, or patient helper under subdivision (j) of Section 4 of Article VII of the California Constitution shall not have a right to mandatory reinstatement.

(d) If an employee in an exempt appointment accepts an extension of the exempt appointment or accepts a new exempt appointment with no break in the continuity of state service in an exempt appointment, subdivision (b) shall apply when the extension or new exempt appointment is terminated.

(e) If an employee exercises his or her right of reinstatement and returns to his or her former position, the service while under an exempt appointment shall be deemed to be time served in the former position for the purpose of determining his or her seniority and eligibility for merit salary increases.

(f) If the termination of an exempt appointment is for a reason contained in Section 19997 and the employee does not have a right to mandatory reinstatement, he or she shall have his or her name placed on the departmental and general reemployment lists for the class of his or her former position.