Cal. Revenue and Taxation Code § 17563.51

(a) For taxable years beginning on or after January 1, 2019, the amendments made by Section 13102(a) of the Tax Cuts and Jobs Act (Public Law 115-97) to Section 447 of the Internal Revenue Code, relating to method of accounting for corporations engaged in farming, shall apply, except as otherwise provided. (b) For taxable years beginning on or after January 1, 2019, the amendments made by Section 13102(e)(2) of the Tax Cuts and Jobs Act (Public Law 115-97), relating to preservation of suspense account rules with respect to any existing suspense accounts, shall apply to any suspense account existing as of the effective date of the act adding this subdivision. (c) For taxable years beginning on or after January 1, 2019, the amendments made by Section 13102(a) of the Tax Cuts and Jobs Act (Public Law 115-97) to Section 448 of the Internal Revenue Code, relating to limitation on use of cash method of accounting, shall apply, except as otherwise provided. (d) For taxable years beginning on or after January 1, 2019, the amendments made by Section 13102(b) of the Tax Cuts and Jobs Act (Public Law 115-97) to Section 263A of the Internal Revenue Code, relating to capitalization and inclusion in inventory cost of certain expenses, shall apply, except as otherwise provided. (e) For taxable years beginning on or after January 1, 2019, the amendments made by Section 13102(c) of the Tax Cuts and Jobs Act (Public Law 115-97) to Section 471 of the Internal Revenue Code, relating to the general rule for inventories, shall apply, except as otherwise provided. (f) (1) Any change in method of accounting made pursuant to this section shall be treated for purposes of applying Section 481 of the Internal Revenue Code, as applicable for California purposes under Section 17551, as initiated by the taxpayer and made with the consent of the Franchise Tax Board. (2) Section 13102(e)(1) of the Tax Cuts and Jobs Act (Public Law 115-97) does not apply to subdivisions (a) to (e), inclusive. (3) (A) Notwithstanding paragraph (2) and except as provided in subparagraph (B), a taxpayer may elect to apply the provisions of this section to taxable years beginning on or after January 1, 2018, and before January 1, 2019. (B) Notwithstanding paragraph (2), a taxpayer may elect to apply the provisions of subdivision (b) to suspense accounts established before the effective date of the act adding this subdivision.