Controversial medical questions may be referred by the workers' compensation commissioner to the physicians designated in section 85A.20 for investigation and report to the workers' compensation commissioner when agreed to by the parties or on the commissioner's own motion. No award shall be made in any case where controversial medical questions have been referred to the physicians until the physicians have duly investigated the case and made a report with respect to all such medical questions. The date of disablement, if in dispute, shall be deemed a medical question.
Iowa Code § 85A.21
86 Acts, ch 1245, §906; 98 Acts, ch 1061, §11