The wikipedia description is horrific enough without me adding anything to it : Prior authorization is a check run by some insurance companies or third-party payers in the United States before they will agree to cover certain prescribed medications or medical procedures.[2] There are a number of reasons that insurance providers require prior authorization, including age, medical necessity, the availability of a generic alternative, or checking for drug interactions.[2][3] A failed authorization can result in a requested service being denied or in an insurance company requiring the patient to go through a separate process known as "step therapy" or "fail first." Step therapy dictates that a patient must first see unsuccessful results from a medication or service preferred by the insurance provider, typically considered either more cost effective or safer, before the insurance company will cover a different service
