California Code, Revenue and Taxation Code - RTC § 18405.1

(a) Notwithstanding Section 18405, the Franchise Tax Board may, in its discretion, permit elections made under Section 25111 to be perfected during the period of limitations prescribed under Sections 19057 and 19306 for the applicable taxable year. The statute of limitations of all taxpayers in a water's-edge group whose taxable year falls, in whole or in part, within the period of the election shall remain open to receive adjustments, under claim or deficiency, consistent with that perfection of the election.

(b) Subdivision (a) does not apply to the 1988 taxable year of any taxpayer whose water's-edge election has been perfected pursuant to Section 18405.