Prior authorization is a requirement that health insurers use to exercise more control over enrollees’ medical treatments. If a health plan requires prior authorization for a specific service and providers fail to obtain approval, the treatment is not reimbursed. Prior authorization is controversial because doctors and patients often see it as an unnecessary interference between the doctor and patient relationship. Doctors hate the hassle of seeking permission prior to treating their patients. They also dislike so-called bean counters second guessing their treatment choices.