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Fax the completed prior authorization form to the fax number printed on your insurance card or listed in the insurer's provider portal, then keep the fax confirmation page: it is your proof of timely filing. Include every procedure and diagnosis code your doctor's office provided, double-check the member ID, and call the insurer a day or two later to confirm the request is actually in their system.
Prior authorization (pre-auth) is your insurer's way of approving a service before you get it: surgeries, MRIs, specialty drugs, physical therapy, and similar high-cost items. The insurer wants to confirm the service is medically necessary under your plan before agreeing to pay. If you skip the step and get the service anyway, the claim can be denied in full, and the bill is yours. The authorization request usually comes from your doctor's office, but patients often end up faxing documents themselves when records are missing or a deadline is tight.
Here is the detail people learn the hard way: prior authorization is plan-specific. What one insurer approves by phone, another requires by fax with clinical notes attached. The rules live in your plan's policy documents, not in the doctor's office, so when something stalls, the fastest fix is asking the insurer's prior-auth line exactly what they are waiting for.
Start with the back of your insurance card: many cards print a dedicated prior-authorization or pharmacy-benefit fax number there. If it is not on the card, check the insurer's website or member portal, or call the member-services number and ask for the prior-auth fax line directly. Be specific about what you are requesting, because insurers run separate fax lines for medical authorizations, pharmacy authorizations, and behavioral health, and a form sent to the wrong line can sit unprocessed for days.
Write the number down twice, once from the source and once as you dial it. A single transposed digit is the most common reason a prior-auth fax "disappears": the confirmation page will cheerfully report success, and the pages will have landed on a stranger's machine.
| What to include | Why it matters |
|---|---|
| Member name, date of birth, member ID | Matches the request to your plan; one wrong digit can route it to someone else |
| Procedure codes (CPT) and diagnosis codes (ICD) | This is what the reviewer actually evaluates; missing codes are the top cause of denials |
| Ordering provider's name, NPI, and contact info | The insurer may need clinical notes or a peer-to-peer review with this doctor |
| Clinical notes or test results supporting the request | Medical necessity is decided on documentation, not on the form alone |
| Requested service date | Authorizations are time-limited; a missing date can delay processing |
| Cover sheet with page count | Confirms nothing was lost in transmission; counts the cover as page 1 |
The fax confirmation page is the whole game. Prior-auth deadlines are real: a request faxed a day late can mean the procedure gets rescheduled. Keep the confirmation page next to a copy of everything you sent, and note the exact time, date, and destination number. If the insurer later claims they never received it, that page is your evidence, and in disputes over timely filing it carries real weight.
Then call. Seriously. Confirmation pages prove transmission, not that a human picked the fax up and entered it into the system. Call the prior-auth line a day or two after faxing, give them your member ID, and ask whether the request is in the queue. If it is not, you can resend immediately instead of discovering the problem the week of the procedure. Ask for a reference or case number on that call and write it down: it becomes the thread you pull if anything goes wrong later.
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