N.Y. EPT Law § 2-1.3

§ 2-1.3 Adopted children and posthumous children as members of a class\n (a) Unless the creator expresses a contrary intention, a disposition\nof property to persons described in any instrument as the issue,\nchildren, descendants, heirs, heirs at law, next of kin, distributees\n(or by any term of like import) of the creator or of another, includes:\n (1) Adopted children and their issue in their adoptive relationship.\nThe rights of adopted children and their issue to receive a disposition\nunder wills and lifetime instruments as a member of such class of\npersons based upon their birth relationship shall be governed by the\nprovisions of subdivision two of section one hundred seventeen of the\ndomestic relations law.\n (2) Children conceived before, but born alive after such disposition\nbecomes effective.\n (3) Nonmarital children. For the purposes of this paragraph, a\nnonmarital child is the child of a mother and is the child of a father\nif the child is entitled to inherit from such father under section 4-1.2\nof this chapter. The provisions of this paragraph shall apply to the\nwills of persons dying on and after September first, nineteen hundred\nninety-one, to lifetime instruments theretofore executed which on said\ndate are subject to the grantor's power to revoke or amend, and to all\nlifetime instruments executed on or after such date.\n