Idaho State Statutes - Idaho Attorney Directory

A contract to make a will or
devise, or not to revoke a will or devise, or to die intestate, if executed
after the effective date of this act, can be established only by (1)
provisions of a will stating material provisions of the contract; (2) an
express reference in a will to a contract and extrinsic evidence proving the
terms of the contract; or (3) a writing signed by the decedent evidencing the
contract. The execution of a joint will or mutual wills does not create a
presumption of a contract not to revoke the will or wills.

Click here to visit the Official Idaho State Statutes