Gov. Code, § 22551

(a) The board may charge or assess a public agency, and the public agency shall pay and reimburse the state at the times and in the amounts as the board may determine, the public agency’s proportionate share of all costs incurred by the state in the administration of the federal system as it affects the public agency and its employees. The charges and assessments may differ from public agency to public agency. The charges or assessments shall be determined by the board in a manner approved by the Department of Finance and may be charged or assessed either in arrears or on the basis of anticipated costs not to exceed one year in advance.

(b) A penalty of 50 percent of the amount charged or assessed shall be added to each charge or assessment that is delinquent 90 days after a notice of the charge or assessment was mailed by the board. The total amount of the charge, assessment, and penalty that remains unpaid after 120 days shall accrue interest at the rate of 7 percent per annum. The charges, assessments, penalties, and interest collected shall be paid into the Treasury and credited as revenue to the Old Age and Survivors’ Insurance Revolving Fund for use by the board upon appropriation by the Legislature pursuant to subdivision (b) of Section 22600.

(c) For charges and assessments levied on state departments and agencies pursuant to this section, the Controller shall transfer funds from those departments and agencies into the Old Age and Survivors’ Insurance Revolving Fund based on a schedule provided by the board and approved by the Department of Finance.