Cal. Gov. Code § 21419
This system shall deduct the amount of advanced disability pension payments made to a local safety member pursuant to Section 4850.3 or 4850.4 of the Labor Code from the member's retroactive disability allowance, and reimburse the local agency that has made the advanced disability pension payments. If the retroactive disability allowance is not sufficient to reimburse the total advanced disability pension payments, an amount no greater than 10 percent of the member's monthly disability allowance shall be deducted and reimbursed to the local agency until the total advanced disability pension payments have been repaid. The local safety member and this system may agree to any other arrangement or schedule for the member to repay the advanced disability pension payments.
Ca. Gov. Code § 21419