Prior authorization is your insurance company's way of checking whether a treatment, medication, or procedure is medically necessary before you get it
When your doctor prescribes something expensive or unusual, your insurance company may require prior authorization — a formal approval process before you can receive the treatment. Your doctor's office submits a request to the insurance company, which reviews the medical details and decides whether to approve it, deny it, or ask for more information. This happens behind the scenes in most cases, but understanding how it works helps you avoid surprise bills and delays.
Prior authorization is not the same as a referral. A referral is your primary care doctor directing you to a specialist. Prior authorization is your insurance company saying "yes, we will pay for this" or "no, we will not" — or sometimes "yes, but only if you try this cheaper option first." It exists because insurance companies want to control costs and prevent unnecessary procedures, though it can also delay care you actually need.
Key Takeaways
- Prior authorization is a required approval from your insurance company before you receive certain treatments, medications, or procedures.
- Your doctor's office usually handles the request, but you should follow up if you do not hear back within a few days, because delays can push back your appointment.
- Insurance companies can approve the request, deny it, or ask your doctor for more clinical information to make a decision.
- If your request is denied, you have the right to appeal, and your doctor can submit additional evidence to support the medical need.
When your insurance company requires prior authorization
Insurance companies do not require prior authorization for every visit or prescription. They typically require it for expensive medications, surgeries, imaging scans like MRIs, mental health treatment beyond a certain number of sessions, and certain specialist visits. The exact list depends on your specific insurance plan — your plan documents or the insurance company's website will show which services need approval.
Some medications are flagged automatically because they are brand-name drugs with cheaper generic alternatives, or because they treat conditions where the insurance company prefers you to try a different medication first. A prior authorization request does not mean your doctor thinks the treatment is experimental or risky; it means your insurance company wants to verify it fits their coverage rules.
How the prior authorization process actually works
Your doctor's office submits a form to your insurance company that includes your diagnosis, the specific treatment being requested, why your doctor believes it is necessary, and sometimes your medical history. The insurance company reviews this information, usually within 24 to 72 hours, though some decisions take longer. They then send a decision back to your doctor's office.
You should ask your doctor's office to submit the request as soon as the treatment is planned, not the day before your appointment. Many offices do this automatically, but if you are scheduling a procedure or starting a new medication, confirm that the prior authorization request has been sent. If you do not hear back within three business days, call your doctor's office and ask for the status — delays here can push back your treatment date.
What happens if your request is approved
Once approved, your insurance company sends a letter or authorization number to your doctor's office. This number proves the treatment is covered, and your office will use it when they bill your insurance. You can usually proceed with the treatment as planned. Some approvals come with conditions — for example, "approved for 12 physical therapy sessions" or "approved only if the generic version is unavailable" — so read the approval letter carefully.
Keep a copy of the approval letter or authorization number for your records. If you receive a bill later that should have been covered, you can reference this number to dispute it.
What to do if your request is denied
A denial does not mean you cannot have the treatment; it means your insurance company will not pay for it at that time. You have options. First, ask your doctor's office why the request was denied — sometimes it is a straightforward fix, like missing information that the insurance company needs. Your doctor can resubmit with additional clinical details.
Second, you can file an appeal. Your insurance company must tell you how to appeal in the denial letter, and you have a legal right to do so. Your doctor can submit additional medical evidence supporting why the treatment is necessary. Appeals often succeed because the first reviewer may not have had complete information, or because your doctor can explain the clinical reasoning more clearly the second time.
Third, if the appeal is also denied, you may be able to request an external review — an independent medical professional outside your insurance company reviews the decision. The rules for external review vary by state and by whether your plan is through your employer or purchased individually.
How prior authorization affects your out-of-pocket costs
Prior authorization does not determine how much you pay out of pocket. Your copay, coinsurance, or deductible stays the same whether the treatment is prior authorized or not. What prior authorization does determine is whether your insurance company will pay their share at all. If a treatment is denied and you proceed anyway, you may owe the full cost, not just your usual copay.
This is why the appeal process matters. If your insurance company denies a treatment your doctor believes is medically necessary, fighting the denial can mean the difference between paying $200 and paying $5,000.
The difference between prior authorization and other insurance checks
Prior authorization happens before you receive care. Concurrent review happens while you are receiving care — for example, if you are admitted to the hospital, the insurance company may review whether you still need to be there. Retrospective review happens after you receive care, when the insurance company decides whether to pay the bill you already received.
You may also encounter step therapy, which is related but different. Step therapy means your insurance company requires you to try a cheaper or less invasive treatment first, and only approves the more expensive option if the first one does not work. This often applies to medications — your insurance may require you to try a generic version before approving a brand-name drug. Step therapy requires prior authorization, but not all prior authorization involves step therapy.
Frequently Asked Questions
Can I get treatment without prior authorization if my insurance requires it?
Yes, but your insurance company will likely deny the claim, and you will owe the full cost. Some people choose to pay out of pocket if they believe the treatment is urgent and prior authorization will cause a harmful delay. Discuss this with your doctor and your insurance company before proceeding.
How long does prior authorization usually take?
Most decisions come back within 24 to 72 hours. Some take up to two weeks. Urgent or emergency requests may be decided the same day. Ask your doctor's office for an estimate based on your specific situation and insurance company.
What if my doctor says the treatment is urgent and cannot wait for prior authorization?
Tell your insurance company it is urgent. Most plans have an expedited review process for time-sensitive treatments. Your doctor's office can request expedited review, which typically means a decision within 24 hours. You may still need to pay upfront and seek reimbursement later if the request is denied.
Do I need prior authorization for every specialist visit?
Not always. Some insurance plans require it for any specialist; others only for certain specialists or certain types of visits. Check your plan documents or call your insurance company to find out which specialists on your list require prior authorization before you schedule.
What information should I give my doctor's office to help with prior authorization?
Provide your insurance member ID, your diagnosis, and any relevant medical history. If you have tried other treatments before, mention that — insurance companies often want to know why a cheaper or more standard option will not work for you. The more complete the picture, the faster the review.