Cal. MVC § 998.313

Notwithstanding any provision of the bond act, if the Treasurer sells bonds under this article for which bond counsel has issued an opinion to the effect that the interest on the bonds is excludable from gross income for purposes of federal income tax, subject to any conditions which may be designated, the Treasurer may establish separate accounts for the investment of bond proceeds and for the earnings on those proceeds, and may use those proceeds or earnings to pay any rebate, penalty, or other payment required by federal law or take any other action with respect to the investment and use of bond proceeds required or permitted under federal law necessary to maintain the tax-exempt status of the bonds or to obtain any other advantage under federal law on behalf of the funds of this state.