The grantor shall be treated as the owner of any portion of a trust in respect of which the beneficial enjoyment of the corpus or the income therefrom is subject to a power of disposition, exercisable by the grantor or a nonadverse party, or both, without the approval or consent of any adverse party.
A power, the exercise of which can only affect the beneficial enjoyment of the income for a period commencing after the occurrence of an event such that a grantor would not be treated as the owner under section 673 if the power were a reversionary interest; but the grantor may be treated as the owner after the occurrence of the event unless the power is relinquished.
A power exercisable only by will, other than a power in the grantor to appoint by will the income of the trust where the income is accumulated for such disposition by the grantor or may be so accumulated in the discretion of the grantor or a nonadverse party, or both, without the approval or consent of any adverse party.
A power to determine the beneficial enjoyment of the corpus or the income therefrom if the corpus or income is irrevocably payable for a purpose specified in section 170(c) (relating to definition of charitable contributions) or to an employee stock ownership plan (as defined in section 4975(e)(7)) in a qualified gratuitous transfer (as defined in section 664(g)(1)).
Subsection (a) shall not apply to a power solely exercisable (without the approval or consent of any other person) by a trustee or trustees, none of whom is the grantor or spouse living with the grantor, to distribute, apportion, or accumulate income to or for a beneficiary or beneficiaries, or to, for, or within a class of beneficiaries, whether or not the conditions of paragraph (6) or (7) of subsection (b) are satisfied, if such power is limited by a reasonably definite external standard which is set forth in the trust instrument. A power does not fall within the powers described in this subsection if any person has a power to add to the beneficiary or beneficiaries or to a class of beneficiaries designated to receive the income or corpus except where such action is to provide for after-born or after-adopted children.