PET scans (Positron Emission Tomography scans) are powerful diagnostic tools often used to detect cancer, heart disease, neurological conditions, and more. But despite their clinical importance, it’s not uncommon for health insurance companies to deny coverage for a PET scan—leaving patients frustrated, confused, and out of pocket.
In this blog post, we’ll break down why insurance might deny a PET scan, what you can do if you’re denied, and how to improve your chances of getting your scan approved in the first place.
What Is a PET Scan and Why Is It Used?
A PET scan is an imaging test that allows doctors to check for diseases in your body using a radioactive substance called a tracer. Unlike CT or MRI scans, PET scans provide information about how your organs and tissues are functioning—not just what they look like.
Common reasons for a PET scan include:
Detecting or monitoring cancer
Evaluating brain disorders like Alzheimer’s or epilepsy
Assessing heart problems and blood flow
Checking the effectiveness of treatment
PET scans are costly (ranging from $3,000 to $6,000), so health insurance providers have strict rules about when and why they’re covered.
Why Insurance Companies Deny PET Scans
There are several reasons your insurance might reject a PET scan claim. Here's a breakdown of the most common ones:
1. Lack of Pre-Authorization
Many insurance plans require pre-authorization before approving expensive diagnostic tests. If your healthcare provider fails to get prior approval—or submits it with missing or incorrect information—your claim can be denied automatically.
Tip: Always ask your doctor or imaging center if the scan has been pre-authorized before the appointment.
2. “Not Medically Necessary”
Even if your doctor orders the scan, the insurer might say it's not medically necessary according to their criteria. They usually follow evidence-based guidelines to decide whether a PET scan is appropriate for your condition.
Example:
PET scans for dementia diagnosis are often denied unless specific symptoms or types of dementia (like Alzheimer’s or frontotemporal dementia) are documented.
PET scans for routine cancer screening may be denied if no symptoms or risk factors are present.
Tip: Your doctor should clearly document the symptoms, diagnosis, and reasons why the scan is essential.
3. Incorrect Coding or Billing Errors
A simple coding mistake by the provider can lead to a denial. PET scans have specific CPT (Current Procedural Terminology) codes, and if the wrong one is used, the insurer may not match it to an approved indication.
Example:
A PET/CT scan ordered but billed under a general PET code might confuse the insurer’s system, leading to denial.
Tip: Double-check the billing codes with your provider and ask them to follow up with your insurer.
4. Out-of-Network Provider
If the scan is performed at a facility outside your insurance network, your claim could be denied or only partially reimbursed.
Tip: Make sure the imaging center is in-network with your insurance company. Call the insurer to confirm before the scan.
5. Coverage Exclusions in Your Policy
Some insurance plans, especially high-deductible or limited-benefit plans, may exclude PET scans altogether for certain diagnoses.
Example:
If you're seeking a PET scan for a research trial, preventive screening, or for an “unapproved” diagnosis, your policy might not cover it.
Tip: Review your health insurance policy or speak with a customer representative before scheduling.
What to Do If Your PET Scan Is Denied
A denial doesn’t mean the end of the road. You have the right to appeal the decision, and many patients win appeals with the right documentation.
Step-by-Step Appeal Process:
Request the denial letter
This letter should explain the reason for denial. It may say the scan was not medically necessary, not covered, or not pre-authorized.Ask your doctor to write a support letter
Your doctor can explain why the scan is essential, include past medical history, previous imaging results, and how the scan will affect your treatment plan.Submit a formal appeal to your insurer
Most companies have 30-60 days to respond. Be sure to include:Doctor's letter
Medical records
Denial letter
Any supporting research or guidelines (such as from the American Cancer Society or ACR)
Request a peer-to-peer review
Your doctor can speak directly with the insurance company’s medical reviewer to explain your case.Contact your state insurance department
If your appeal is denied and you feel the decision is unjustified, file a complaint with your state’s department of insurance.
How to Avoid PET Scan Denials
Verify insurance coverage in advance
Ensure pre-authorization is obtained
Keep records of all communications
Use in-network providers only
Ask your provider to use precise, accurate medical codes and documentation
Speak to your insurer directly if you're unsure what’s covered
What Conditions Are Commonly Approved for PET Scans?
Insurers are more likely to approve PET scans for:
Diagnosing and staging cancers (lung, lymphoma, breast, colorectal, etc.)
Assessing cancer treatment response
Detecting recurrence of known cancer
Brain disorders with strong diagnostic criteria (Alzheimer’s, epilepsy, Parkinson’s)
Cardiac perfusion imaging for coronary artery disease
Always check your insurer’s medical policy for PET scans, which outlines covered indications.
🗨️ Real Patient Experiences
“My PET scan for suspected lung cancer was denied, even though I had previous CT findings. It was finally approved after my doctor spoke directly to the insurer.”
— A patient from California
“The scan was denied because the notes didn’t include the word ‘Alzheimer’s.’ Once we fixed the referral and appealed, it was approved in 2 weeks.”
— Reddit user sharing an appeal win
Final Thoughts
A denied PET scan can feel discouraging, but it’s often due to administrative or procedural issues—not because the scan isn’t valuable. By understanding your policy, working closely with your healthcare provider, and knowing your rights, you can navigate the system more confidently and improve your chances of approval or appeal success.