California Code, Revenue and Taxation Code - RTC § 19916

(a) This part shall only become operative if the operation of Section 164(b)(6) of the Internal Revenue Code,  1 relating to the limitation on individual deductions for taxable years 2018 through 2025, is extended.

(b) Except as provided in subdivision (c), this part shall remain in effect only until December 1, 2031, and as of that date is repealed.

(c) If before December 1, 2031, Section 164(b)(6) of the Internal Revenue Code, is repealed, this part would become inoperative for taxable years beginning on or after the January 1 after Section 164(b)(6) of the Internal Revenue Code is repealed, and this part shall be repealed as of December 1 of that year.