California Code, Health and Safety Code - HSC § 116761.65

(a) The board shall establish, and may periodically adjust, the interest rate for repayable financing made pursuant to this chapter at a rate not to exceed 50 percent of the average interest rate, computed by the true interest cost method, paid by the state on general obligation bonds issued in the prior calendar year, rounded up to the closest one-tenth of 1 percent.

(b) Notwithstanding subdivision (a), to the extent authorized by federal law, the board may provide reduced or 0 percent financing to further the purposes of this chapter.