N.Y. Comp. Codes R. & Regs. tit. 12, § 325-6.6 – Time to request arbitration.

(a) A health insurer requesting arbitration must send such request for arbitration to the dispute forum on the HIMP-1 form, in accordance with sections 325-6.7 and 325-6.15 of this Subpart:
1. (1) within 90 days after the date on which the carrier served its notice of objection on the HIMP-1 form to the health insurer; or
2. (2) if the carrier has not made payment or served an objection to the health insurer: Notwithstanding the foregoing, the parties may mutually agree in writing to extend the period in which the carrier must reply to a request for reimbursement.
  1. (i) within 90 days from the expiration of the period within which an objection or payment was required to be made; and
  2. (ii) in no event earlier than 95 days from the date on which the HIMP-1 form requesting reimbursement was initially sent by the health insurer to the carrier.
(b) Where the health insurer has served a timely request for reimbursement, as defined in this Subpart, and has served or supplemented its claim for reimbursement by sending a HIMP-1 form to the carrier, and the carrier has objected or failed to object in accordance with section 325-6.4 of this Subpart, the health insurer shall be deemed to have waived its right to arbitration if such request for arbitration is not timely served on the dispute forum in accordance with the provisions of subdivision (a) of this section.
(c) In any case in which a request for arbitration has been served based on the failure of a carrier to make payment or send notice of objection to the request within 90 days after the request for reimbursement has been made, the carrier shall be deemed to have waived any objections it may have been entitled to interpose pursuant to section 325-6.4(b) and (c) of this Subpart, except as provided in section 325-6.11(c) of this Subpart.