14-2514. Contracts regarding wills; requirements; effect A. After December 31, 1994, a person may enter into a contract to make a will or devise or not to revoke a will or devise or to die intestate only by: 1. Provisions of a will that state the material provisions of the contract. 2. An express reference in a will to a contract and extrinsic evidence proving the terms of the contract. 3. A writing signed by the decedent evidencing the contract. B. The execution of a joint will or mutual wills does not create a presumption of a contract not to revoke the will or wills.
Arizona Legal Code