N.Y. Real Property Actions & Proceedings Law § 1311

§ 1311. Necessary defendants. Each of the following persons, whose\ninterest is claimed to be subject and subordinate to the plaintiff's\nlien, shall be made a party defendant to the action:\n 1. Every person having an estate or interest in possession, or\notherwise, in the property as tenant in fee, for life, by the curtesy,\nor for years, and every person entitled to the reversion, remainder, or\ninheritance of the real property, or of any interest therein or\nundivided share thereof, after the determination of a particular estate\ntherein.\n 2. Every person having a right of dower or an inchoate right of dower\nin the real property or any part or share thereof.\n 3. Every person having any lien or incumbrance upon the real property\nwhich is claimed to be subject and subordinate to the lien of the\nplaintiff.\n 4. Where the mortgage is upon any of the public utilities regulated by\nthe public service law, the public service commission.\n