N.Y. Gen. Oblig. Law § 5-1554

§ 5-1554. Revocation of designation. A parent may revoke a designation\nby notifying, either orally or in writing, the designee or a school,\nhealth care provider, or health plan to which the designation has been\npresented, or by any other act evidencing a specific intent to revoke\nthe designation. A designation shall also be revoked upon the execution\nby the parent of a subsequent designation. Revocation by one parent\nauthorized to execute such a designation shall be deemed effective and\ncomplete revocation of a designation pursuant to this title. A designee\nwho receives notification from a parent of any such revocation shall\nforthwith notify any school, health care provider or health plan to\nwhich a designation pursuant to this title has been presented. A parent\nmay directly notify any such school, health care provider or health plan\nof the revocation, in which case the failure of the designee to notify\nsuch entities of the revocation shall not make revocation ineffective.\n