N.Y. Comp. Codes R. & Regs. tit. 14, § 635-11.3 – PDP enrollment and reviews for persons not residing in a residential facility or a family care home.

(a) If a person has the ability to choose a PDP, the person may enroll himself or herself in a PDP or appoint another party to enroll him or her. If a person has the ability to act in the Part D review process, the person may act in the Part D review process for himself or herself or appoint another party to act in the Part D review process for him or her.
(b) If a person lacks the ability to choose a PDP, but has a guardian lawfully empowered to enroll him or her in a PDP, the guardian may enroll the person in a PDP or appoint another party to enroll the person. If a person lacks the ability to act in the Part D review process, but has a guardian lawfully empowered to act in the Part D review process for the person, the guardian may act in the Part D review process or appoint another party to act in the Part D review process for the person.
(c) If the person is a minor and does not have a guardian lawfully empowered to enroll him or her in a PDP or to act in the Part D review process, a parent may enroll the person or act in the Part D review process, or may appoint another party to enroll the person or act in the Part D review process.
(d) In all other situations, or if any party specified in subdivisions (a)-(c) of this section who would otherwise enroll the person or act in the Part D review process is unwilling or unavailable, any of the following parties may enroll the person, act in the Part D review process or appoint another party to act in the Part D review process:
1. (1) an actively involved: spouse, parent, adult child, adult sibling, adult family member or friend, an advocate or correspondent; or
2. (2) if none of the above are willing and available, the CEO (or designee) of the agency providing service coordination for the person.