N.Y. Comp. Codes R. & Regs. tit. 18 § 505.37
Collateral services are services that would otherwise be reimbursed as MA services and which are provided to a family member or significant other of an MA recipient, regardless of their eligibility for MA, who has an interim or final individualized family services plan. For purposes of this section, a significant other is a person who substitutes for the recipient's family, interacts regularly with the recipient, and affects directly the recipient's developmental status. Collateral services are physicians services, nursing services, nurse practitioner services, audiology services, psychiatric services, psychological services, and rehabilitation services. Payment is available for collateral services furnished pursuant to an interim or final individualized family services plan and which are provided by an approved early intervention program or a municipality in the State. Collateral services must relate to the medical treatment specified in the recipient's interim or final individualized family services plan and must be for the recipient's direct benefit. Persons who receive collateral services must be identified in the interim or final individualized family services plan. Reimbursement for such services must be made in accordance with the provider agreement.
N.Y. Comp. Codes R. & Regs. Tit. 18 § 505.37