(a) Tax on income of certain foreign organizations
In lieu of the tax imposed by section 4940, there is hereby imposed for each taxable year on the gross investment income (within the meaning of section 4940(c)(2)) derived from sources within the United States (within the meaning of section 861) by every foreign organization which is a private foundation for the taxable year a tax equal to 4 percent of such income.

(b) Certain sections inapplicable
Section 507 (relating to termination of private foundation status), section 508 (relating to special rules with respect to section 501(c)(3) organizations), and this chapter (other than this section) shall not apply to any foreign organization which has received substantially all of its support (other than gross investment income) from sources outside the United States.

(c) Denial of exemption to foreign organizations engaged in prohibited transactions

(1) General rule
A foreign organization described in subsection (b) shall not be exempt from taxation under section 501(a) if it has engaged in a prohibited transaction after December 31, 1969.

(2) Prohibited transactions
For purposes of this subsection, the term "prohibited transaction" means any act or failure to act (other than with respect to section 4942(e)) which would subject a foreign organization described in subsection (b), or a disqualified person (as defined in section 4946) with respect thereto, to liability for a penalty under section 6684 or a tax under section 507 if such foreign organization were a domestic organization.

(3) Taxable years affected

(A) Except as provided in subparagraph (B), a foreign organization described in subsection (b) shall be denied exemption from taxation under section 501(a) by reason of paragraph (1) for all taxable years beginning with the taxable year during which it is notified by the Secretary that it has engaged in a prohibited transaction. The Secretary shall publish such notice in the Federal Register on the day on which he so notifies such foreign organization.

(B) Under regulations prescribed by the Secretary, any foreign organization described in subsection (b) which is denied exemption from taxation under section 501(a) by reason of paragraph (1) may, with respect to the second taxable year following the taxable year in which notice is given under subparagraph (A) (or any taxable year thereafter), file claim for exemption from taxation under section 501(a). If the Secretary is satisfied that such organization will not knowingly again engage in a prohibited transaction, such organization shall not, with respect to taxable years beginning with the taxable year with respect to which such claim is filed, be denied exemption from taxation under section 501(a) by reason of any prohibited transaction which was engaged in before the date on which such notice was given under subparagraph (A).

(4) Disallowance of certain charitable deductions
No gift or bequest shall be allowed as a deduction under section 170, 545(b)(2), 642(c), 2055, 2106(a)(2), or 2522, if made—

(A) to a foreign organization described in subsection (b) after the date on which the Secretary publishes notice under paragraph (3)(A) that he has notified such organization that it has engaged in a prohibited transaction, and

(B) in a taxable year of such organization for which it is not exempt from taxation under section 501(a) by reason of paragraph (1).