GOV §31680.9: (a) A person who has been retired under the retirement system, for service or for disability, may not be employed in any capacity thereafter by the county or a district of the retirement system unless

(a) A person who has been retired under the retirement system, for service or for disability, may not be employed in any capacity thereafter by the county or a district of the retirement system unless the person has first been reinstated from retirement pursuant to this chapter, or unless the employment, without reinstatement, is authorized by this article or the California Public Employees’ Pension Reform Act of 2013. A retired person whose employment without reinstatement is authorized by this article or the California Public Employees’ Pension Reform Act of 2013 shall acquire no service credit or retirement rights under this part with respect to the employment. (b) Any retired member employed in violation of Section 31680.2, 31680.3, 31680.6, or 7522.56 shall do all of the following: (1) Reimburse the retirement system for any retirement allowance received during the period or periods of employment that are in violation of law. The retirement allowance that was paid in violation of law shall be considered an overpayment subject to collection by the retirement system. (2) Only if reinstated, pay to the retirement system an amount of money equal to the employee contributions that would otherwise have been paid during the period or periods of unlawful employment, plus interest thereon. (3) Contribute toward reimbursement of the retirement system for reasonable administrative expenses incurred in responding to this situation, to the extent the member is determined by the retirement system administrator to be at fault. (c) Any public employer that employs a retired member in violation of Section 31680.2, 31680.3, 31680.6, or 7522.56 shall do both of the following: (1) Only if the retired member is reinstated, pay to the retirement system an amount of money equal to employer contributions that would otherwise have been paid for the period or periods of time that the member is employed in violation of this article, plus interest thereon. (2) Contribute toward reimbursement of the retirement system for reasonable administrative expenses incurred in responding to this situation, to the extent the employer is determined by the administrator of the retirement system to be at fault. (d) If an employer fails to report, in a format determined by the system for the administrative recordkeeping purposes of the system, a retired member employed in any capacity, without reinstatement, within 30 days of the effective date of hire, the board may assess the employer a fee of two hundred dollars ($200) per retired member per month until the information is reported. (e) If an employer fails to report the pay rate and number of hours worked of a retired member employed in any capacity, without reinstatement, at periods determined by the system, the board may assess the employer a fee of two hundred dollars ($200) per retired member per month until the information is reported. (f) An employer shall not pass on to an employee any fees assessed pursuant to subdivisions (d) and (e). (g) The employer shall provide written notice to the employee, by an appropriate mechanism, including by first-class mail or email, before the employee is within 10 business days or 80 hours of the period of time included in Section 31680.2, 31680.3, 31680.6, or 7522.56.