Medical insurance rejections sometimes happens for a number of factors. A easy cause may be billing error from the supplier office. In case the claim is filed using the incorrect therapy or diagnostic code, then the claim might be denied. More significant reasons can involve treatments known as «experimental» or»pre-existing». Both these reasons might be deducted should you have the insurance company’s decision isn’t right. http://www.insuranceclaimdenialappeal.com/2010/05/co-contractual-obligations-denial-code.html