MRI Scan Denied by Insurance: How to Appeal 'Not Medically Necessary'

You've been having symptoms. Your doctor recommended an MRI to figure out what's wrong. You have insurance. It should be covered, right?

But then the denial letter arrives: "Not medically necessary."

This denial is incredibly frustrating because from your perspective, the MRI clearly IS necessary—your doctor ordered it. But insurance companies use their own clinical guidelines, and those guidelines are often more restrictive than standard medical practice. The good news? These denials are frequently reversible with the right appeal strategy.

Why Insurance Denies MRI Scans

Understanding the insurer's reasoning is your first step toward fighting back.

Violating Imaging Guidelines

Insurance companies rely on clinical guidelines (often from organizations like the American College of Radiology, or ACR) to determine whether imaging is necessary. These guidelines attempt to prevent unnecessary testing. But guidelines are general; they don't account for individual patient complexity.

For example, ACR guidelines might say MRI is only indicated for back pain if conservative treatment has failed for 6+ weeks. If you've only tried treatment for 3 weeks, the insurer denies based on the guideline—ignoring that your specific situation might warrant earlier imaging.

Insufficient Prior Conservative Treatment

Many insurers require that you've exhausted conservative treatment (physical therapy, medication, rest) before imaging is approved. If you haven't tried these, they deny the MRI. But sometimes imaging is appropriate before conservative treatment—if your doctor suspects a serious structural problem, waiting could delay necessary treatment.

"Routine" Surveillance When You Have a Known Condition

If you have a condition like a herniated disc or a small benign tumor, insurance may deny routine follow-up MRIs saying they're not medically necessary. They may argue that the condition hasn't changed, so imaging isn't needed. But sometimes regular surveillance is the medically appropriate approach to detecting change.

Alternative Imaging Available

Insurance may deny MRI saying CT or X-ray would suffice. While those are often cheaper, MRI is sometimes medically superior for specific questions. If your doctor chose MRI for good clinical reasons, this denial may be reversible.

Deemed "Investigative" Rather Than "Diagnostic"

Insurance sometimes argues that an MRI is exploratory—you don't have a clear diagnosis, so you're just hoping imaging will find something. But diagnostic imaging ordered to evaluate symptoms is standard medical practice, not exploratory.

Getting Your Doctor to Support Your Appeal

This is absolutely critical. An insurance company will not reverse a denial without strong physician advocacy.

Schedule a Conversation With Your Doctor

Call your doctor's office and explain the situation. Say: "My insurance denied the MRI you recommended, saying it's not medically necessary. Would you be willing to write a letter explaining why you believe it is medically necessary for my specific situation?"

Most doctors will help. This is part of their job—advocating for their patients when insurance denies necessary care.

What Should the Letter Include?

Ask your doctor to address specifically what the insurance company claimed. The letter should include:

If insurance cited guidelines: "While ACR guidelines suggest conservative treatment first, my evaluation of this patient shows [specific clinical findings] that warrant earlier imaging. Delaying imaging risks [specific risk or delayed diagnosis]."

If insurance said alternative imaging suffices: "For this patient's presentation, MRI is necessary rather than CT because [specific clinical reason]. CT would not adequately address the diagnostic question because [explanation]."

If insurance said surveillance isn't necessary: "Regular surveillance MRI is medically appropriate for this patient because [specific clinical concern], and changes since the last imaging would affect management."

If insurance said symptoms aren't severe enough: "This patient's symptoms are limiting their function and quality of life, and the severity justifies imaging to identify the cause."

The letter should also explain what you have or haven't tried. If you haven't done physical therapy yet but your doctor still believes MRI is necessary, the letter should explain why. For example: "MRI would help determine whether physical therapy is appropriate or if structural pathology requires different management."

Get a Second Opinion If Needed

If your doctor is reluctant to write a strong letter, consider getting a second opinion from another physician in the same specialty. That physician can write a letter supporting the MRI. Insurance is more likely to reverse a denial when multiple physicians agree the imaging is necessary.

Understanding Insurance Medical Guidelines

To appeal effectively, you need to understand what guidelines the insurance company is actually using.

Request the Specific Guideline

Ask your insurer in writing: "What specific clinical guideline or medical criteria did you apply when denying my MRI? Please provide the document."

Most insurers will provide it. Once you have it, read it carefully. Look for:

• Exceptions to the main guideline
• Language that says "generally" or "typically" (suggesting flexibility)
• Qualifications like "unless clinical judgment indicates otherwise"

These exceptions and qualifications become your appeal argument.

Research the Guidelines Yourself

Major imaging guidelines are published and publicly available:

• American College of Radiology (ACR) Appropriateness Criteria (acr.org)
• American Academy of Neurology guidelines
• Specialty-specific societies (orthopedic, rheumatology, etc.)

Look up the guideline for your specific condition and symptom. You'll often find that imaging is appropriate in more situations than the insurer acknowledged. Your appeal can cite these nuances.

Show Exceptions Apply to You

Even restrictive guidelines have exceptions. For example, ACR might say "MRI not indicated for mechanical back pain unless neurologic deficit present." If you have a neurologic deficit, you're an exception, and you should point this out.

Building Your MRI Appeal Letter

Your appeal should be structured, clear, and evidence-based.

Opening

State clearly: "I am appealing [Insurance Company]'s denial of MRI of [body part] on [date]. I believe this denial was based on an incorrect application of medical guidelines to my specific situation."

Your Clinical Picture

Describe your symptoms and condition in detail:

• When did symptoms start?
• What are you experiencing (pain, numbness, weakness, etc.)?
• How is this affecting your function?
• What treatments have you tried? For how long? With what results?

This section helps the reviewer understand why imaging is necessary for YOUR situation.

Why MRI Specifically

Explain why your doctor chose MRI:

• "MRI is superior to CT for [specific reason related to your condition]"
• "My symptoms suggest [specific pathology] which requires MRI to visualize"
• "Alternative imaging would not adequately address [the diagnostic question]"

Addressing the Insurance Reason for Denial

The most important section. If the insurance company said:

"Not medically necessary by guidelines": Explain why you're an exception or why the guideline supports imaging in your case.

"Conservative treatment not exhausted": Explain why your doctor recommends imaging anyway, or explain why you have tried conservative measures.

"Symptoms not severe enough": Describe the functional impact and why earlier imaging is warranted.

"Alternative imaging sufficient": Explain why MRI is specifically necessary for your situation.

Enclosed Evidence

List all attached documents:

• Doctor's letter supporting the MRI
• Relevant medical records
• Imaging guideline documentation
• Any second opinion letters
• Your symptom timeline

Closing

End with: "Based on [physician] supporting the medical necessity of this MRI, and based on my specific clinical presentation, I request that [Insurance] reverse this denial and approve the MRI scan."

Common Insurance Objections and Responses

Insurance often uses predictable objections. Here's how to respond to each.

"The guideline says conservative treatment first"

Response: "While the guideline typically suggests conservative treatment first, [physician] has determined that my specific presentation warrants imaging now because [specific clinical reason]. Delaying imaging could result in [specific consequence]."

"Symptoms might resolve without imaging"

Response: "While some conditions self-resolve, my symptoms have [persisted/worsened] for [timeframe], and the severity and functional impact warrant determining the underlying cause. Continuing to wait without diagnosis could delay necessary treatment."

"MRI is expensive"

Response: "Cost cannot be the determining factor for medically necessary care. The guideline focuses on medical necessity, not cost. The cost should not influence coverage decisions."

"You haven't tried our preferred provider"

Response: "I am willing to have the MRI at your preferred provider. Please approve the MRI with [specified provider]."

Timeline: Act Quickly

Most insurance companies give you 180 days (USA) or similar timeframes to appeal. But don't wait:

• File your appeal within 2 weeks of receiving the denial
• Aim to have your doctor's letter attached to the appeal
• If insurance doesn't respond within 30 days, follow up
• If they deny your appeal, prepare for external review or regulator escalation

Ready to Appeal Your MRI Denial?

Fighting an insurance denial requires strategy and persistence. The appeal letter needs to address the insurer's specific stated reason, include strong physician support, and be organized so the reviewer quickly understands your situation.

ClaimBack's AI reviews your denial letter, understands exactly what the insurer objected to, helps you organize evidence, and drafts a compelling appeal letter that your doctor will support. You review, edit, and send it—maintaining full control.

Get your free MRI appeal analysis →

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Disclaimer: ClaimBack provides AI-generated appeal assistance for informational purposes only. ClaimBack is not a law firm and does not provide legal advice. Always review your appeal letter before sending and consider professional advice for complex or high-value claims.

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