Missouri Revised Statutes Title X. Taxation and Revenue § 143.171. Federal income tax deduction, amount, corporate and individual taxpayers

1. For all tax years beginning on or after January 1, 1994, and ending on or before December 31, 2018, an individual taxpayer shall be allowed a deduction for his or her federal income tax liability under Chapter 1 of the Internal Revenue Code  1 for the same taxable year for which the Missouri return is being filed, not to exceed five thousand dollars on a single taxpayer's return or ten thousand dollars on a combined return, after reduction for all credits thereon, except the credit for payments of federal estimated tax, the credit for the overpayment of any federal tax, and the credits allowed by the Internal Revenue Code by 26 U.S.C. Section 31,  226 U.S.C. Section 27,  3 and 26 U.S.C. Section 34.  4

3. For all tax years beginning on or after September 1, 1993, a corporate taxpayer shall be allowed a deduction for fifty percent of its federal income tax liability under Chapter 1 of the Internal Revenue Code for the same taxable year for which the Missouri return is being filed after reduction for all credits thereon, except the credit for payments of federal estimated tax, the credit for the overpayment of any federal tax, and the credits allowed by the Internal Revenue Code by 26 U.S.C. Section 31, 26 U.S.C. Section 27, and 26 U.S.C. Section 34.

4. If a federal income tax liability for a tax year prior to the applicability of sections 143.011 to 143.996 for which he was not previously entitled to a Missouri deduction is later paid or accrued, he may deduct the federal tax in the later year to the extent it would have been deductible if paid or accrued in the prior year.