N.Y. Est. Powers & Trusts Law § 7-1.1

§ 7-1.1 When trust interests not to merge\n A trust is not merged or invalid because a person, including but not\nlimited to the creator of the trust, is or may become the sole trustee\nand the sole holder of the present beneficial interest therein, provided\nthat one or more other persons hold a beneficial interest therein,\nwhether such interest be vested or contingent, present or future, and\nwhether created by express provision of the instrument or as a result of\nreversion to the creator's estate.\n