Ariz. Rev. Stat. § 20-3603
A. An asset or a reduction from liability for the reinsurance ceded by a domestic insurer to an assuming insurer that does not meet the requirements of section 20-3602 shall be allowed in an amount not exceeding the liabilities carried by the ceding insurer. The director may adopt by rule pursuant to section 20-3604, subsection B specific additional requirements relating to or prescribing any or all of the following:
B. The reduction shall be in the amount of funds held by or on behalf of the ceding insurer, including funds held in trust for the ceding insurer, under a reinsurance contract with the assuming insurer as security for the payment of obligations thereunder, if the security is held in the United States subject to withdrawal solely by, and under the exclusive control of, the ceding insurer or, in the case of a trust, held in a qualified United States financial institution as defined in section 20-3601, subsection B. This security may be in the form of: