(1) For purposes of the income tax imposed by the provisions of the Nebraska Revenue Act of 1967, a taxpayer's taxable year shall be the same as his taxable year for federal income tax purposes.

(2) If a taxpayer's taxable year is changed for federal income tax purposes, his taxable year for purposes of the income tax imposed by the provisions of the Nebraska Revenue Act of 1967 shall be similarly changed in accordance with regulations prescribed by the Tax Commissioner.

(3) Notwithstanding the provisions of subsections (1) and (2) of this section, if the Tax Commissioner terminates the taxpayer's taxable year under the provisions of section 77-27,111, relating to tax in jeopardy, the income tax shall be computed for the period determined by such action in accordance with regulations prescribed by the Tax Commissioner.