Iowa Code § 633A.6101: Subject matter jurisdiction.

1. The district court sitting in probate has exclusive jurisdiction of proceedings concerning the internal affairs of a trust and of actions and proceedings to determine the existence of a trust, actions and proceedings by or against creditors or debtors of a trust, and other actions and proceedings involving a trust and third persons. Such jurisdiction may be invoked by any interested party at any time.

2. Unless a trust is under continuous court supervision pursuant to section 633.10, subsection 4, the trust shall not be subject to the jurisdiction of the probate court and the court shall not issue letters of appointment.