Carryback and carryforward of unused credits
In general
1-year carryback and 20-year carryforward
If the sum of the business credit carryforwards to the taxable year plus the amount of the current year business credit for the taxable year exceeds the amount of the limitation imposed by subsection (c) of section 38 for such taxable year (hereinafter in this section referred to as the “unused credit year”), such excess (to the extent attributable to the amount of the current year business credit) shall be—
a business credit carryback to the taxable year preceding the unused credit year, and
a business credit carryforward to each of the 20 taxable years following the unused credit year,
and, subject to the limitations imposed by subsections (b) and (c), shall be taken into account under the provisions of section 38(a) in the manner provided in section 38(a).
Amount carried to each year
Entire amount carried to first year
Amount carried to other 20 years
5-year carryback for marginal oil and gas well production credit
Notwithstanding subsection (d), in the case of the marginal oil and gas well production credit—
this section shall be applied separately from the business credit (other than the marginal oil and gas well production credit),
paragraph (1) shall be applied by substituting “each of the 5 taxable years” for “the taxable year” in subparagraph (A) thereof, and
paragraph (2) shall be applied—
by substituting “25 taxable years” for “21 taxable years” in subparagraph (A) thereof, and
by substituting “24 taxable years” for “20 taxable years” in subparagraph (B) thereof.
Limitation on carrybacks
The amount of the unused credit which may be taken into account under section 38(a)(3) for any preceding taxable year shall not exceed the amount by which the limitation imposed by section 38(c) for such taxable year exceeds the sum of—
the amounts determined under paragraphs (1) and (2) of section 38(a) for such taxable year, plus
the amounts which (by reason of this section) are carried back to such taxable year and are attributable to taxable years preceding the unused credit year.