the term high income threshold amount means— (i) except as provided in clause (ii) or (iii), $400,000, (ii) in the case of a taxpayer making a joint return under section 6013 or a surviving spouse (as defined in section 2(a)), $500,000, and (iii) in the case of a married taxpayer (as defined in section 7703) filing a separate return, 1/2 of the dollar amount determined under clause (ii). (B) Specified net income For purposes of this section, the term specified net income means net investment income determined— (i) without regard to the phrase other than such income which is derived in the ordinary course of a trade or business not described in paragraph (2), in subsection (c)(1)(A)(i), (ii) without regard to the phrase described in paragraph (2) in subsection (c)(1)(A)(ii), (iii) without regard to the phrase other than property held in a trade or business not described in paragraph (2) in subsection (c)(1)(A)(iii), (iv) without regard to paragraphs (2), (3), and (4) of subsection (c), and (v) by treating paragraphs (5) and (6) of section 469(c) (determined without regard to the phrase To the extent provided in regulations, in such paragraph (6)) as applying for purposes of subsection (c) of this section. . (b) Application to trusts and estates Section 1411(a)(2) of the Internal Revenue Code of 1986 is amended— (1) by striking 3.8 percent and inserting 17.4 percent , and (2) in subparagraph (A) thereof, by striking undistributed net investment income and inserting the greater of undistributed specified net income or undistributed net investment income . (c) Clarifications with respect to determination of net investment income (1) Certain exceptions Section 1411(c)(6) of the Internal Revenue Code of 1986 is amended to read as follows: (6) Special rules Net investment income shall not include— (A) any item taken into account in determining self-employment income for such taxable year on which a tax is imposed by section 1401(b), (B) wages received with respect to employment on which a tax is imposed under section