Cal. Rev. & Tax. Code § 17563.5
(b) In the case of any taxpayer required by enactment of this section to change the method of accounting, for that taxpayer’s first taxable year beginning on or after January 1, 2002, each of the following shall apply for purposes of this part, Part 10.2 (commencing with Section 18401), and Part 11 (commencing with Section 23001):