(6) Special rules (A) Married individuals In the case of a husband or wife who files a separate return, the amount specified under subparagraph (B) of paragraph (1) shall be $12,500 in lieu of $25,000. This subparagraph shall not apply if the spouse of the taxpayer has no business credit carryforward or carryback to, and has no current year business credit for, the taxable year of such spouse which ends within or with the taxpayer’s taxable year. (B) Controlled groups In the case of a controlled group, the $25,000 amount specified under subparagraph (B) of paragraph (1) shall be reduced for each component member of such group by apportioning $25,000 among the component members of such group in such manner as the Secretary shall by regulations prescribe. For purposes of the preceding sentence, the term “controlled group” has the meaning given to such term by section 1563(a). (C) Limitations with respect to certain persons In the case of a person described in subparagraph (A) or (B) of section 46(e)(1) (as in effect on the day before the date of the enactment of the Revenue Reconciliation Act of 1990), the $25,000 amount specified under subparagraph (B) of paragraph (1) shall equal such person’s ratable share (as determined under section 46(e)(2) (as so in effect) of such amount. (D) Estates and trusts In the case of an estate or trust, the $25,000 amount specified under subparagraph (B) of paragraph (1) shall be reduced to an amount which bears the same ratio to $25,000 as the portion of the income of the estate or trust which is not allocated to beneficiaries bears to the total income of the estate or trust. (E) Corporations In the case of a corporation, this subsection shall be applied by treating the corporation as having a tentative minimum tax of zero.
26 USC § 38(c)(6)
None identified, default scope is assumed to be the parent (subpart D) of this section.