California Code, Revenue and Taxation Code - RTC § 17224

(a) For taxable years beginning on or after January 1, 1987, and before the taxable year in which the debt obligation matures or is sold, exchanged, or otherwise disposed, the amount deductible under this part is the same as the amount deductible on the federal tax return.

(b) The difference between the amount deductible on the federal tax return and the amount allowable under this part, with respect to obligations issued after December 31, 1984, for taxable years beginning before January 1, 1987, shall be allowed as a deduction in the taxable year in which the debt obligation matures or is sold, exchanged, or otherwise disposed.

(c) The provisions of Section 7202(c) of Public Law 101-239,  2 relating to the effective date for treatment of certain high yield original issue discount obligations, shall apply.