How the Common Law Fills in the Gaps
No statute can cover every situation that might arise in trust administration. Arizona's trust code handles the major topics, but when a question falls outside the written rules, courts turn to the common law of trusts and general principles of equity to resolve it.
The common law of trusts and principles of equity supplement this chapter, except to the extent modified by this chapter or another statute of this state.
A.R.S. § 14-10106(A)In practice, this means Arizona trust law has two layers. The statute comes first. Where the statute is silent, judges apply principles developed over centuries of trust case law. These common law principles cover topics like the duty of loyalty, the duty of impartiality between beneficiaries, and the standards for trustee decision-making.
Which Restatement Guides the Court
Legal scholars have published several versions of the Restatement of Trusts, each reflecting evolving views on trust law. Arizona made a deliberate choice about which version controls.
The court shall look to the restatement (second) of trusts for interpretation of the common law and not to subsequent restatements of trusts to determine: 1. The rights and powers of creditors of beneficiaries. 2. The duties of trustees to distribute to those to whom a beneficiary owes any duties. 3. Whether public policy may affect enforceability and effectiveness of the terms of the trust. 4. And effectuate the settlor's intent.
A.R.S. § 14-10106(B)This distinction matters. The Restatement (Third) of Trusts, published later, took different positions on creditor rights, trustee distribution duties, and the role of public policy in trust enforcement. By locking in the Second Restatement, Arizona provides more predictable outcomes on these specific issues. For families creating or administering trusts in Arizona, this means the rules around creditor access to trust assets and spendthrift protections follow the more traditional framework.
