California Code, Education Code - EDC § 23008

(a) If more or less than the required contributions specified in this part and Section 44987 are paid to the system based on any payment of creditable compensation to a member, proper adjustments shall be made on a monthly report, by the county superintendent, district superintendent, chancellor of a community college district, or other employing agency who submitted the report, within 60 days after discovery or notification by the system and any refunds shall be made to the member within the same time period by the employing agency.

(b) The board shall, in accordance with regulations, assess penalties for late or improper adjustments pursuant to Section 23006. These penalties shall be no more than the regular interest as defined in Section 22162. The penalty so assessed shall be deemed interest earned in the year in which it was received.