((a)) ** Qualified domestic trust defined** For purposes of this section and section 2056(d), the term “qualified domestic trust” means, with respect to any decedent, any trust if—

((1)) the trust instrument—

((A)) except as provided in regulations prescribed by the Secretary, requires that at least 1 trustee of the trust be an individual citizen of the United States or a domestic corporation, and

((B)) provides that no distribution (other than a distribution of income) may be made from the trust unless a trustee who is an individual citizen of the United States or a domestic corporation has the right to withhold from such distribution the tax imposed by this section on such distribution,

((2)) such trust meets such requirements as the Secretary may by regulations prescribe to ensure the collection of any tax imposed by subsection (b), and

((3)) an election under this section by the executor of the decedent applies to such trust.

((b)) ** Tax treatment of trust**

((1)) ** Imposition of estate tax** There is hereby imposed an estate tax on—

((A)) any distribution before the date of the death of the surviving spouse from a qualified domestic trust, and

((B)) the value of the property remaining in a qualified domestic trust on the date of the death of the surviving spouse.

((2)) ** Amount of tax**

((A)) ** In general** In the case of any taxable event, the amount of the estate tax imposed by paragraph (1) shall be the amount equal to—

((i)) the tax which would have been imposed under section 2001 on the estate of the decedent if the taxable estate of the decedent had been increased by the sum of—

((I)) the amount involved in such taxable event, plus

((II)) the aggregate amount involved in previous taxable events with respect to qualified domestic trusts of such decedent, reduced by

((ii)) the tax which would have been imposed under section 2001 on the estate of the decedent if the taxable estate of the decedent had been increased by the amount referred to in clause (i)(II).

((B)) ** Tentative tax where tax of decedent not finally determined**

((i)) ** In general** If the tax imposed on the estate of the decedent under section 2001 is not finally determined before the taxable event, the amount of the tax imposed by paragraph (1) on such event shall be determined by using the highest rate of tax in effect under section 2001 as of the date of the decedent’s death.

((ii)) ** Refund of excess when tax finally determined** If—

((I)) the amount of the tax determined under clause (i), exceeds

((II)) the tax determined under subparagraph (A) on the basis of the final determination of the tax imposed by section 2001 on the estate of the decedent,

((C)) ** Special rule where decedent has more than 1 qualified domestic trust** If there is more than 1 qualified domestic trust with respect to any decedent, the amount of the tax imposed by paragraph (1) with respect to such trusts shall be determined by using the highest rate of tax in effect under section 2001 as of the date of the decedent’s death (and the provisions of paragraph (3)(B) shall not apply) unless, pursuant to a designation made by the decedent’s executor, there is 1 person—

((i)) who is an individual citizen of the United States or a domestic corporation and is responsible for filing all returns of tax imposed under paragraph (1) with respect to such trusts and for paying all tax so imposed, and

((ii)) who meets such requirements as the Secretary may by regulations prescribe.

((3)) ** Certain lifetime distributions exempt from tax**

((A)) ** Income distributions** No tax shall be imposed by paragraph (1)(A) on any distribution of income to the surviving spouse.

((B)) ** Hardship exemption** No tax shall be imposed by paragraph (1)(A) on any distribution to the surviving spouse on account of hardship.

((4)) ** Tax where trust ceases to qualify** If any qualified domestic trust ceases to meet the requirements of paragraphs (1) and (2) of subsection (a), the tax imposed by paragraph (1) shall apply as if the surviving spouse died on the date of such cessation.

((5)) ** Due date**

((A)) ** Tax on distributions** The estate tax imposed by paragraph (1)(A) shall be due and payable on the 15th day of the 4th month following the calendar year in which the taxable event occurs; except that the estate tax imposed by paragraph (1)(A) on distributions during the calendar year in which the surviving spouse dies shall be due and payable not later than the date on which the estate tax imposed by paragraph (1)(B) is due and payable.

((B)) ** Tax at death of spouse** The estate tax imposed by paragraph (1)(B) shall be due and payable on the date 9 months after the date of such death.

((6)) ** Liability for tax** Each trustee shall be personally liable for the amount of the tax imposed by paragraph (1). Rules similar to the rules of section 2204 shall apply for purposes of the preceding sentence.

((7)) ** Treatment of tax** For purposes of section 2056(d), any tax paid under paragraph (1) shall be treated as a tax paid under section 2001 with respect to the estate of the decedent.

((8)) ** Lien for tax** For purposes of section 6324, any tax imposed by paragraph (1) shall be treated as an estate tax imposed under this chapter with respect to a decedent dying on the date of the taxable event (and the property involved shall be treated as the gross estate of such decedent).

((9)) ** Taxable event** The term “taxable event” means the event resulting in tax being imposed under paragraph (1).

((10)) ** Certain benefits allowed**

((A)) ** In general** If any property remaining in the qualified domestic trust on the date of the death of the surviving spouse is includible in the gross estate of such spouse for purposes of this chapter (or would be includible if such spouse were a citizen or resident of the United States), any benefit which is allowable (or would be allowable if such spouse were a citizen or resident of the United States) with respect to such property to the estate of such spouse under section 2014, 2032, 2032A, 2055, 2056, 2058, or 6166 shall be allowed for purposes of the tax imposed by paragraph (1)(B).

((B)) ** Section 303** If the estate of the surviving spouse meets the requirements of section 303 with respect to any property described in subparagraph (A), for purposes of section 303, the tax imposed by paragraph (1)(B) with respect to such property shall be treated as a Federal estate tax payable with respect to the estate of the surviving spouse.

((C)) ** Section 6161(a)(2)** The provisions of section 6161(a)(2) shall apply with respect to the tax imposed by paragraph (1)(B), and the reference in such section to the executor shall be treated as a reference to the trustees of the trust.

((11)) ** Special rule where distribution tax paid out of trust** For purposes of this subsection, if any portion of the tax imposed by paragraph (1)(A) with respect to any distribution is paid out of the trust, an amount equal to the portion so paid shall be treated as a distribution described in paragraph (1)(A).

((12)) ** Special rule where spouse becomes citizen** If the surviving spouse of the decedent becomes a citizen of the United States and if—

((A)) such spouse was a resident of the United States at all times after the date of the death of the decedent and before such spouse becomes a citizen of the United States,

((B)) no tax was imposed by paragraph (1)(A) with respect to any distribution before such spouse becomes such a citizen, or

((C)) such spouse elects—

((i)) to treat any distribution on which tax was imposed by paragraph (1)(A) as a taxable gift made by such spouse for purposes of—

((I)) section 2001, and

((II)) determining the amount of the tax imposed by section 2501 on actual taxable gifts made by such spouse during the year in which the spouse becomes a citizen or any subsequent year, and

((ii)) to treat any reduction in the tax imposed by paragraph (1)(A) by reason of the credit allowable under section 2010 with respect to the decedent as a credit allowable to such surviving spouse under section 2505 for purposes of determining the amount of the credit allowable under section 2505 with respect to taxable gifts made by the surviving spouse during the year in which the spouse becomes a citizen or any subsequent year,

((13)) ** Coordination with section 1015** For purposes of section 1015, any distribution on which tax is imposed by paragraph (1)(A) shall be treated as a transfer by gift, and any tax paid under paragraph (1)(A) shall be treated as a gift tax.

((14)) ** Coordination with terminable interest rules** Any interest in a qualified domestic trust shall not be treated as failing to meet the requirements of paragraph (5) or (7) of section 2056(b) merely by reason of any provision of the trust instrument permitting the withholding from any distribution of an amount to pay the tax imposed by paragraph (1) on such distribution.

((15)) ** No tax on certain distributions** No tax shall be imposed by paragraph (1) on any distribution to the surviving spouse to the extent such distribution is to reimburse such surviving spouse for any tax imposed by subtitle A on any item of income of the trust to which such surviving spouse is not entitled under the terms of the trust.

((c)) ** Definitions** For purposes of this section—

((1)) ** Property includes interest therein** The term “property” includes an interest in property.

((2)) ** Income** Except as provided in regulations, the term “income” has the meaning given to such term by section 643(b).

((3)) ** Trust** To the extent provided in regulations prescribed by the Secretary, the term “trust” includes other arrangements which have substantially the same effect as a trust.

((d)) ** Election** An election under this section with respect to any trust shall be made by the executor on the return of the tax imposed by section 2001. Such an election, once made, shall be irrevocable. No election may be made under this section on any return if such return is filed more than one year after the time prescribed by law (including extensions) for filing such return.

((e)) ** Regulations** The Secretary shall prescribe such regulations as may be necessary or appropriate to carry out the purposes of this section, including regulations under which there may be treated as a qualified domestic trust any annuity or other payment which is includible in the decedent’s gross estate and is by its terms payable for life or a term of years.