Cal. Government Code § 19838

(a) When the state determines an overpayment has been made to an employee, it shall notify the employee of the overpayment and afford the employee an opportunity to respond prior to commencing recoupment actions. Thereafter, reimbursement shall be made to the state through one of the following methods mutually agreed to by the employee and the state: (1) Cash payment or payments. (2) Installments through payroll deduction to cover at least the same number of pay periods in which the error occurred. When overpayments have continued for more than one year, full payment may be required by the state through payroll deductions over the period of one year. (3) The adjustment of appropriate leave credits or compensating time off, provided that the overpayment involves the accrual or crediting of leave credits (e.g., vacation, annual leave, or holiday) or compensating time off. Any errors in sick leave balances may only be adjusted with sick leave credits. Absent mutual agreement on a method of reimbursement, the state shall proceed with recoupment in the manner set forth in paragraph (2). (b) An employee who is separated from employment prior to full repayment of the amount owed shall have withheld from any money owing the employee upon separation an amount sufficient to provide full repayment. If the amount of money owing upon separation is insufficient to provide full reimbursement to the state, the state shall have the right to exercise any and all other legal means to recover the additional amount owed. (c) Amounts deducted from payment of salary or wages pursuant to the above provisions, except as provided in subdivision (b), shall in no event exceed 25 percent of the employee’s net disposable earnings. (d) An administrative action shall not be taken by the state pursuant to this section to recover an overpayment unless the action is initiated within three years from the date of overpayment. If an overpayment involves leave credits, the date of overpayment is the date that the employee receives compensation in exchange for leave erroneously credited to the employee. For purposes of this section, leave hours are considered exchanged for compensation in the order they were credited. (e) If the provisions of this section are in conflict with the provisions of a memorandum of understanding reached pursuant to Section 3517.5, the memorandum of understanding shall be controlling without further legislative action, except that if the provisions of a memorandum of understanding require the expenditure of funds, the provisions shall not become effective unless approved by the Legislature in the annual Budget Act.