Your doctor ordered an MRI, and then your insurance company said no. A prior authorization denial is frustrating, but it often isn’t the final word. Many denials are about missing paperwork rather than whether you need the scan, and you have the legal right to appeal. Here’s what to do, step by step.
Key takeaways
- A denial usually means the insurer didn’t get enough information, not that the scan can never be approved.
- Your doctor can often fix it quickly by sending more records or asking for a peer-to-peer review.
- If that fails, you can file an internal appeal with your insurer, and then ask for an independent external review.
- If waiting could seriously harm your health, ask for an expedited (fast) appeal.
- Don’t skip a scan your doctor says you need just because of a denial. Talk to your doctor about your options.
Why MRI prior authorizations get denied
Insurers compare each request with their own coverage rules, which are often based on clinical guidelines. Common reasons for a denial include:
- Missing information: the request didn’t include notes, symptoms or exam findings that support the scan.
- Other treatment first: the plan wants proof that you tried other treatment first, such as physical therapy or medication for back pain.
- A different test first: the plan wants an X-ray or ultrasound before an MRI.
- Coding errors: the procedure or diagnosis code didn’t match the request.
- Network or site of care: the imaging center is out of network, or the plan prefers a lower-cost location.
- Not medically necessary: the insurer decided the scan wouldn’t change your care.
The denial letter should tell you the reason. Under a federal rule that took effect in 2026, Medicare Advantage, Medicaid, CHIP and federal Marketplace plans must give a specific reason for prior authorization denials.
Step 1: Read the denial letter carefully
Look for:
- The exact reason for the denial.
- The coverage policy or guideline the insurer used.
- Your appeal deadline.
- How to file an appeal and whether an expedited appeal is available.
Call your insurer and ask for a copy of the clinical policy they used. You have the right to see it.
Step 2: Call your doctor’s office
Your doctor’s office often handles prior authorizations, and they may already know about the denial. Ask:
- Did the request include all your records?
- Can they resubmit with more information?
- Can your doctor request a peer-to-peer review?
In a peer-to-peer review, your doctor talks directly with a doctor working for the insurer. It’s often the fastest way to overturn a denial, because your doctor can explain why you need the MRI.
Step 3: Ask whether a different plan of action fits
Sometimes the insurer will approve a different path, such as an X-ray first, a different MRI protocol or a different imaging center. Your doctor can tell you whether that’s medically reasonable for you. That decision belongs to you and your doctor, not the insurer.
Step 4: File an internal appeal
If the denial stands, file a formal appeal with your insurer. The deadlines depend on your type of coverage.
Private insurance (employer or Marketplace plans):
| Step | Deadline |
|---|---|
| You file the internal appeal | Within 180 days of the denial notice |
| Insurer decides (scan not yet done) | Within 30 days |
| Insurer decides (urgent) | As fast as your condition requires, and no later than 4 business days |
Medicare Advantage:
| Step | Deadline |
|---|---|
| You request a reconsideration | Within 65 days of the denial notice |
| Plan decides (standard) | Within 30 days |
| Plan decides (fast appeal) | Within 72 hours |
If a Medicare Advantage plan upholds its denial, it must send your case to an Independent Review Entity automatically.
Medicaid: appeal rules are set by your state. Your denial notice explains them.
What to include in your appeal
- A copy of the denial letter.
- A letter from your doctor explaining why you need the MRI (a letter of medical necessity).
- Relevant medical records: symptoms, exam findings, earlier test results and treatments you’ve tried.
- Your own short letter (see the template below).
Keep copies of everything, and send it in a way you can track.
Step 5: Ask for an external review
If your insurer denies your internal appeal, you can usually ask for an external review. An independent reviewer looks at your case, and the insurer no longer gets the final say.
| Step | Deadline |
|---|---|
| You request external review | Within 4 months of the final denial |
| Reviewer decides (standard) | Within 45 days |
| Reviewer decides (urgent) | Within 72 hours |
External review is free under the federal process, and state processes can charge no more than $25.
Step 6: Get help if you need it
- Your state insurance department or consumer assistance program can help with private plans.
- Your State Health Insurance Assistance Program (SHIP) offers free help with Medicare Advantage.
- Your employer’s HR or benefits office can help with job-based plans.
Appeal letter template
You can adapt this short letter. Fill in the parts in brackets.
[Your name] [Member ID and claim or reference number] [Date]
To: [Insurance company] Appeals Department
I am requesting an appeal of the denial of prior authorization for an MRI of the [body part], ordered by Dr. [name] on [date]. The denial letter dated [date] states the reason as [reason].
My doctor believes this MRI is medically necessary because [short reason, for example: symptoms have lasted X weeks despite treatment]. I have attached a letter of medical necessity from my doctor and relevant medical records.
[If urgent: My doctor believes waiting for a standard decision could seriously harm my health. I am requesting an expedited appeal.]
Please send me a copy of the clinical criteria used in this decision. Thank you for your review.
[Signature]
What about paying out of pocket?
If the timing matters, some people pay a cash price for the MRI while the appeal continues. Ask the imaging center for its self-pay price first. Keep in mind that if you go ahead without approval, your insurer may not reimburse you even if you win the appeal later. Check with your insurer before you decide.
Frequently asked questions
How long does an MRI prior authorization take? It varies. Since 2026, Medicare Advantage, Medicaid, CHIP and federal Marketplace plans must generally decide within 7 calendar days for standard requests and 72 hours for urgent ones. Other plans follow their own and state timelines.
Can I appeal on my own, without my doctor? Yes, but your doctor’s support makes a big difference. A letter of medical necessity is usually the most important part of an appeal.
What is an expedited appeal? It’s a faster process for cases where waiting could seriously harm your health. Your doctor usually needs to support the request.
Do appeals actually work? Many denials are reversed on appeal, especially when the problem was missing information. Every case is different.
Sources
- HealthCare.gov: Internal appeals and External review.
- Medicare.gov: Appeals in Medicare health plans.
- Association of American Medical Colleges (AAMC): Summary of the CMS Interoperability and Prior Authorization Final Rule.
This article is for general information only and isn’t medical, legal or financial advice. Check your plan documents and denial notice for the deadlines that apply to you.