Gov. Code, § 99015

(a) The authority may provide for the issuance of bonds any portion of which is to be used for the purpose of refunding outstanding bonds, including the payment of the principal thereof and interest and redemption premiums, if any, thereon. The proceeds of bonds issued to refund any outstanding bonds may be applied to the retirement of those outstanding bonds at maturity, or the redemption, on any redemption date, or purchase of the outstanding bonds prior to maturity, upon the terms and subject to the conditions the authority shall deem advisable.

(b) Notwithstanding any other provision of this title, the authority may not issue refunding bonds with a final maturity date later than the final maturity date of the series of bonds being refunded, unless the Legislature has adopted legislation by a two-thirds vote of each house, extending the imposition of a special sales tax or taxes to provide for payment of the refunding bonds. This subdivision shall not apply to bonds issued to refund bond anticipation notes issued pursuant to subdivision (c) of Section 99011.