Cal. Health & Safety Code § 33645.5

Notwithstanding Section 33645 or any other provision of law, the rate of interest on any indebtedness or obligation of an agency which is payable to the federal government or any agency or instrumentality thereof or on any such indebtedness or obligation guaranteed by the federal government or any instrumentality thereof may be at a rate higher than the limitation established in Section 33645, or any other law, if such rate is the rate established by the federal government or any instrumentality thereof. Any such indebtedness or obligation shall be in such form and denomination, have such maturity, and be subject to such conditions as may be prescribed by the federal government or agency or instrumentality thereof.