(1) With respect to each taxable year commencing on or after January 1, 1987, but prior to January 1, 2000, for every individual, estate, and trust, in addition to the tax imposed in section 39-22-104, a tax is imposed in an amount equal to the excess of:

(a) Three and seventy-five one-hundredths percent of the Colorado alternative minimum taxable income, as determined pursuant to subsection (2) of this section; over

(b) The tax imposed in section 39-22-104.

(1.5) With respect to each taxable year commencing on or after January 1, 2000, for every individual, estate, and trust, in addition to the tax imposed in section 39-22-104, a tax is imposed in an amount equal to the excess of:

(a) Three and forty-seven one-hundredths percent of the Colorado alternative minimum taxable income, as determined pursuant to subsection (2) of this section; over

(b) The tax imposed in section 39-22-104.

(2)

(a) The Colorado alternative minimum taxable income shall be the federal alternative minimum taxable income, as determined pursuant to section 55 of the internal revenue code, minus the applicable federal exemptions allowed pursuant to such section, with the modifications provided in section 39-22-104; except that any state or local bond interest included in the federal alternative minimum taxable income shall not be added back in determining the Colorado alternative minimum taxable income, and any interest income from obligations of the state of Colorado or any political subdivision thereof which is exempt from the Colorado tax imposed pursuant to the provisions of section 39-22-104 (3)(b) shall be subtracted from the federal alternative minimum taxable income to the extent included therein in determining Colorado alternative minimum taxable income.

(b) In any case, should the tax determined under the provisions of this section for a taxable year beginning on or after January 1, 1987, but before January 1, 1988, exceed the tax imposed by this section as it existed on June 22, 1987, then only the smaller tax shall apply.

(3)

(a) For taxable years beginning on or after January 1, 1988, but prior to January 1, 2000, each individual, estate, and trust shall be allowed a credit against the tax imposed by this part 1 in an amount equal to eighteen percent of the credit allowed for the same tax year by section 53 of the internal revenue code.

(b) For taxable years beginning on or after January 1, 2000, each individual, estate, and trust shall be allowed a credit against the tax imposed by this part 1 in an amount equal to twelve percent of the credit allowed for the same tax year by section 53 of the internal revenue code.

(4) In the case of a nonresident taxpayer, the tax imposed by subsections (1) and (1.5) of this section and the credit allowed by subsection (3) of this section shall be apportioned in the ratio of the modified federal alternative minimum taxable income from Colorado sources over the total modified federal alternative minimum taxable income.