Cal. Gov. Code § 31593
The retirement board shall conduct an audit of the retirement system at least once every 12 months and report upon its financial condition. The retirement board may retain the services of a certified public accountant to perform the annual audit. That audit shall be performed in accordance with generally accepted auditing standards. The cost of the audit shall be considered a cost of the administration of the retirement system. The audit report shall address the financial condition of the retirement system, internal accounting controls, and compliance with applicable laws and regulations. A copy of the audit report shall be filed with the board of supervisors.
Nothing in this section shall preclude the retirement board from selecting the county auditor to perform the annual audit, and if so done, the cost of that audit shall be considered a cost of the administration of the retirement system.
At the request of the county board of supervisors, the county auditor may audit the accounts of the retirement system. The expense of that audit shall not be a cost chargeable by the county to the retirement system.
Ca. Gov. Code § 31593