Iowa Code § 633.471: Right of retainer.

When a distributee of an estate is indebted to the estate, or if a distributee takes as an heir of a deceased devisee indebted to the estate, the amount of such indebtedness, if due, or the present worth of the indebtedness, if not due, shall be treated as a setoff and retained by the personal representative out of any testate or intestate property, real or personal, of the estate to which such distributee is entitled. In intestate estates, the personal representative shall have the same right of setoff and retainer against an heir whose ancestor was indebted to the estate. The right of setoff and retainer shall be prior and superior to the rights of judgment creditors, heirs or assigns of such distributee.