How to Initiate Prior Authorization With Express Scripts


Certain prescription medications need to be preapproved by Express Scripts before they will be covered. This preapproval process is known as prior authorization. If you do not receive approval for drugs requiring prior authorization, you may pay the full cost of the medication.

In general, prior authorization may be required for drugs that have dangerous side effects; are harmful when combined with other drugs; should be used only for certain health conditions; are often misused or abused; or are prescribed when less expensive alternatives might work better.

Drugs requiring prior authorization are noted with a “PA” on the preferred list of medications for non-Medicare enrollees, as well as the formulary for Medicare enrollees. Express Scripts previously mailed these documents to enrolled members based on Medicare status:

Your doctor can initiate the prior authorization process by calling Express Scripts toll-free at 800‑417‑8164 or by fax at 800‑357‑9577. If you plan to fill your prescription at a retail pharmacy, consider completing the prior authorization with your doctor before you go to the pharmacy. A registered pharmacist working at the retail pharmacy may also initiate or assist with the process.

Here are some important reminders about prior authorization:

  • If the medication is not approved, you will pay the full cost of the prescription. However, you may appeal the rejection by following the procedures outlined in the appeals section of your Express Scripts plan coverage documents.
  • Be aware, a prior authorization covers a limited time period and must be renewed when the authorization expires. Most approvals are valid for up to one year.
  • When renewing an authorization, begin the process early enough to allow sufficient time to fill the prescription before it runs out or to make alternative plans in case the medication is no longer covered.

If you have questions about prior authorization, call Express Scripts toll-free at 866‑685‑2792 (non-Medicare enrollees) or 888‑416‑3326 (Medicare enrollees). You can also visit