Mass. Gen. Laws ch. 184B § 3
The following discretionary powers, which shall be known as the "Statutory Disability Discretionary Powers", may be conferred by reference upon any fiduciary, and, unless otherwise provided in the instrument by which it is conferred, shall apply to all distributions to be made under the terms of the instrument or under powers or discretions granted to the fiduciary by the instrument to a minor, to a person under such other age as may be specified in the instrument, or to a person whom the fiduciary determines to be unable to properly care for his property by reason of advanced age, mental weakness or physical incapacity:
The fiduciary may make distribution to any person to whom this discretion is applicable or apply or distribute the same for his benefit or account, or retain all or any part of the same, whether principal or income, in trust for him and thereafter at any time or times distribute part or all to him or apply or distribute the same for his benefit or account. When the discretion hereunder terminates, whether by reason of the age, or otherwise, the fiduciary shall distribute any property retained in trust for such person hereunder to such person, or to his guardian or conservator or to his estate, as the case may be. Such discretion shall not apply to any distribution to which the spouse, surviving spouse or surviving child of the testator or settlor making the instrument is entitled either outright or under a trust or share which qualifies for a marital or orphan deduction under applicable federal tax laws, except that distributions may be made to or applied for the benefit of such spouse, surviving spouse or surviving child, as the case may be.
Mass. Gen. Laws ch. 184B, § 3