Cal. Rev. & Tax. Code § 17133

Income which this state is prohibited from taxing includes interest on bonds issued by this state or a local government in this state, and the determination of whether a bond is issued by this state or a local government in this state shall be made without regard to (a) the source of payment of that bond or the security for that bond, public or private, and (b) whether or not public improvements are financed. If there is at any time following the original issuance of such a bond a separation in ownership between the bond and any right to receive interest on the bond (whether or not evidenced by a coupon), payments or accruals on that stripped bond and stripped coupon shall be treated in a manner consistent with Section 1286(d) of the Internal Revenue Code.