The party who would suffer loss if an issue were not established has the burden of proving that issue by a preponderance of the evidence. Iowa R. of App. Section 86.13 permits an award of up to 50 percent of the amount of benefits delayed or denied if a delay in commencement or termination of benefits occurs without reasonable or probable cause or excuse. The standard for evaluating the reasonableness of defendants' delay in commencement or termination is whether the claim is fairly debatable. Where a claim is shown to be fairly debatable, defendants do not act unreasonably in denying payment.
Imposition is mandatory when there has been any uneplained delay or denial.
The burden of showing cause for any delay or denial is on the employer. Case law has further refined the issue of when an award of penalty benefits is mandated. In that case, we will defer to the decision of the commissioner. For the purpose of applying section 86.13, the benefits that are under paid as well as late -paid benefits are subject to penalties, unless the employer establishes reasonable and probable cause or excuse. For these reasons, we conclude section 86.13 is applicable when payment of compensation is not timely . . .