For medically necessary services, a prior authorization acts as a guideline for what the insurance will and will not cover. There may be an alternative treatment, such as a similar prescription drug or service, that is covered by the plan. In that case, your doctor will switch you to this service. However, if you need a specific treatment that is not currently covered, you can ask us to make an exception to our coverage rules. We will take your health needs into account when we make our decision. Learn more about coverage exceptions.