New York Consolidated Laws, Insurance Law - ISC § 5105. Settlement between insurers

(a) Any insurer liable for the payment of first party benefits to or on behalf of a covered person and any compensation provider paying benefits in lieu of first party benefits which another insurer would otherwise be obligated to pay pursuant to subsection (a) of section five thousand one hundred three of this article or section five thousand two hundred twenty-one of this chapter has the right to recover the amount paid from the insurer of any other covered person to the extent that such other covered person would have been liable, but for the provisions of this article, to pay damages in an action at law.  In any case, the right to recover exists only if at least one of the motor vehicles involved is a motor vehicle weighing more than six thousand five hundred pounds unloaded or is a motor vehicle used principally for the transportation of persons or property for hire.  However, in the case of occupants of a bus other than operators, owners, and employees of the owner or operator of the bus, an insurer which, pursuant to paragraph one of subsection (a) of section five thousand one hundred three of this article, provides coverage for first party benefits for such occupants under a policy providing first party benefits to the injured person and members of his household for loss arising out of the use or operation of any vehicle of such household, shall have no right to recover the amount of such benefits from the insurer of such bus.

(b) The sole remedy of any insurer or compensation provider to recover on a claim arising pursuant to subsection (a) hereof, shall be the submission of the controversy to mandatory arbitration pursuant to procedures promulgated or approved by the superintendent.  Such procedures shall also be utilized to resolve all disputes arising between insurers concerning their responsibility for the payment of first party benefits.

(c) The liability of an insurer imposed by this section shall not affect or diminish its obligations under any policy of bodily injury liability insurance.