Does Medicare Cover PET Scans? Coverage, Costs, and What to Expect

Understanding medical tests can feel overwhelming, especially when you are unsure about the costs involved. If your doctor has recommended a PET scan, you likely have questions about what the test involves, why you need it, and whether your Medicare plan will help pay for it.

Understanding your benefits is an important part of managing your health. This guide explains the ins and outs of PET scans, how they differ from other imaging tests, and exactly how Medicare coverage works for these diagnostic procedures.

What Is a PET Scan?

A positron emission tomography (PET) scan is an advanced imaging test that allows doctors to see how your organs and tissues are functioning. While standard X-rays or ultrasounds take pictures of your bones and organs, a PET scan goes a step further. It looks at vital functions on a cellular level, such as blood flow, oxygen use, and how your body uses sugar (glucose).

This unique view helps doctors find problems that might not show up on other types of scans. Because disease often begins with biological changes at the cellular level, a PET scan can sometimes detect illness earlier than other tests.

How the PET Scan Works

To see tiny details, a PET scan uses a small amount of a radioactive substance called a tracer. This tracer is usually given through an injection into a vein in your arm, though sometimes it can be swallowed, or inhaled as a gas.

Once the tracer enters your body, it travels through your blood and collects in organs and tissues. The tracer gives off tiny energy particles that the PET scanner detects. The scanner then turns this information into detailed 3-D images. Areas of your body that are very active—like cancer cells, which use more energy than healthy cells—absorb more of the tracer and light up brightly on the scan.

Why Doctors Order This Test

Your doctor might order a PET scan for several important reasons. It is most commonly used to:

• Detect cancer: It can show where cancer is, if it has spread, and how it is responding to treatment.
• Check heart function: It helps reveal areas of the heart that have been damaged or scarred, often due to a heart attack. It can also show if areas of the heart are receiving enough blood flow.
• Evaluate brain disorders: Doctors use PET scans to help diagnose conditions like Alzheimer's disease, epilepsy, and Parkinson's disease by looking at brain activity and blood flow.

PET Scan vs. CT Scan: Understanding the Difference

It is very common for patients to confuse PET scans with CT (computed tomography) scans. Both machines look like large doughnuts, and both require you to lie on a flat table that slides into a tunnel. However, they provide very different types of information.

Category	CT scan	PET scan
Main purpose	Shows anatomy/structure (shape, size, location).	Shows function/metabolic activity (how tissues are working).
What it can reveal best	Fractures, bleeding, organ changes, masses/tumors that change structure.	Areas of unusually high/low activity (for example, active tumors, heart muscle viability, certain brain activity patterns).
How it works	Uses X-rays taken from many angles to create cross-sectional images.	Uses a small amount of radioactive tracer that “lights up” active tissues on the scan.
Common reasons doctors order it	Injury/trauma evaluation, abdominal pain, lung issues, tumor sizing and location, many urgent diagnoses.	Cancer staging/monitoring, heart blood flow and tissue viability, evaluation of some brain disorders.
Appointment timing (typical)	Often faster overall; the scan portion is usually minutes.	Longer visit because of tracer uptake time; scan portion often ~30–45 minutes.
Preparation (typical)	Varies by exam; some require contrast and/or fasting.	Often requires fasting and specific diet/activity instructions beforehand to avoid affecting results.
Results/images	Detailed pictures of structures and abnormalities in anatomy.	3-D images that highlight metabolic “hot spots” and “cold spots.”
Radiation	Includes ionizing radiation from X-rays.	Includes radiation from the tracer (and may also include CT radiation if done as PET/CT).

The CT Scan: Looking at Structure

Think of a CT scan as a highly detailed architectural photo of a building. It uses special X-ray equipment to create cross-sectional pictures of the body. It is excellent at showing the shape, size, and location of bones, organs, and tumors. If you have a broken bone or a tumor that has grown large enough to change the shape of an organ, a CT scan will see it clearly.

The PET Scan: Looking at Function

If the CT scan is a photo of the building, the PET scan is like a thermal image that shows where the electricity is running inside. It shows biological activity. For example, a tumor might look like normal tissue on a CT scan, but on a PET scan, it might glow brightly because it is biologically active and growing fast.

The Combined PET/CT Scan

Today, many hospitals use a machine that combines both scans together in a single exam. This is called a PET/CT scan. By merging the two images, doctors get the best of both worlds: they can see the exact location of a tumor (from the CT part) and know exactly how active it is (from the PET part). This provides a more accurate diagnosis than either test could offer alone.

Does Medicare Cover PET Scans?

Yes, Medicare covers PET scans, but there are specific rules regarding when and why they are covered. Medicare coverage usually depends on "medical necessity." This means your doctor must say that the test is needed to diagnose or treat your illness or injury.

What Does Medicare Part B Cover for PET Scans?

For most people with Original Medicare, diagnostic tests like PET scans fall under Medicare Part B (Medical Insurance).

Medicare Part B covers PET scans if:

• Your doctor orders the test.
• The test is performed at a facility that accepts Medicare.
• The scan is used to diagnose or manage a covered condition, specifically certain types of cancer, heart conditions, or brain disorders.

For cancer specifically, Medicare covers PET scans to help determine the stage of the cancer (how far it has spread) and to see if treatment is working. Medicare may also cover one PET scan to help guide treatment for early-stage solid tumors or amyloidosis (a rare protein disorder).

Coverage for Alzheimer's and Dementia

Historically, Medicare limited coverage for PET scans related to Alzheimer's disease. However, rules have evolved. Medicare may cover specialized PET scans (known as Beta Amyloid PET scans) if they are part of a clinical trial or strictly used to rule out other causes of dementia. It is important to ask your doctor about coverage if you are seeking a diagnosis for memory issues.

Medicare Advantage Plans (Part C)

If you have a Medicare Advantage plan (like those offered by Wellcare), your plan must provide at least the same level of coverage as Original Medicare. This means if Original Medicare covers a PET scan for your condition, your Medicare Advantage plan will too.

However, Medicare Advantage plans often have different rules regarding networks and approvals. You may need to:

• Get a referral from your primary care doctor.
• Obtain "prior authorization" (approval from the plan) before having the test done.
• Use a specific network of hospitals or imaging centers to get the lowest cost.

Always check with your plan provider before scheduling your scan to ensure you are following the correct steps.

What You Will Pay: The Cost of a Pet Scan with Insurance

Even with coverage, you typically have some out-of-pocket costs for a PET scan.

If you have Original Medicare:

• Deductible: You must pay your Part B annual deductible before Medicare starts to pay.
• Coinsurance: Once your deductible is met, you usually pay 20% of the Medicare-approved amount for the scan. Medicare pays the remaining 80%.
• Facility Fees: If you have the scan at a hospital outpatient department, you may also have to pay a separate copayment to the hospital.

If you have a Medicare Advantage Plan: Your costs will vary depending on your specific plan. Instead of a percentage (like 20%), you might pay a flat copayment (for example, $50 or $100) for diagnostic imaging. You should review your plan's "Evidence of Coverage" or call member services to find out the exact cost share for diagnostic radiology.

2026 Medicare Limits (Deductibles, Coinsurance, and Out-of-Pocket Protection)

When people say “Medicare limits,” they are usually talking about the yearly deductibles and cost-sharing amounts set by Medicare, plus whether there is a cap on what you pay out of pocket. These amounts can change from year to year.

Limits at a Glance

Item	2026 limit (and what it means)
Part B deductible	$283 per year. After you meet it, you typically pay 20% coinsurance of the Medicare-approved amount for Part B services (including most outpatient diagnostic tests), and Medicare pays 80%.
Original Medicare out-of-pocket max	None. Original Medicare does not have an annual out-of-pocket maximum for Part A and Part B services.
Medicare Advantage (Part C) MOOP	Varies by plan. Medicare Advantage plans set a yearly limit on what you pay out of pocket for covered Part A and Part B services.
Part A inpatient hospital deductible	$1,736 per benefit period. Longer stays may have coinsurance (for example, $434/day for days 61–90 and $868/day for lifetime reserve days).

If you have a Medicare Supplement (Medigap) Plan: If you have Original Medicare and a Medigap policy, your Medigap plan may help pay for the 20% coinsurance that Medicare does not cover. Some plans also cover the Part B deductible.

How to Prepare for Your PET Scan

Proper preparation is essential for a PET scan. Because the test relies on how your body processes sugar, what you eat and do before the exam can drastically change the results. If you do not follow the instructions, you may have to reschedule the test.

The Day Before the Exam

• Diet: Your doctor will likely ask you to follow a low-carbohydrate, no-sugar diet for 24 hours before the scan. Avoid pasta, bread, potatoes, cereals, and sweets. Instead, eat meat, hard cheeses, tofu, or eggs.
• Hydration: Drink plenty of water. Being well-hydrated helps the technician find your veins and helps flush the tracer out of your body after the test.
• Exercise: Avoid strenuous exercise for 24 hours before the scan. Exercise draws sugar to your muscles, which can interfere with the images.

The Day of the Exam

• Fasting: You usually cannot eat anything for at least 6 hours before your appointment. You can (and should) drink plain water, but avoid coffee, tea, soda, or juice. Even sugar-free gum or mints can affect the test results.
• Medications: Ask your doctor about your medications. You can usually take them with water, but if you take medication for diabetes, you will need special instructions.
• Diabetes Care: If you have diabetes, your blood sugar levels must be within a specific range for the test to work. Your doctor may ask you to take your insulin at a different time.
• Clothing: Wear comfortable, loose-fitting clothes. Avoid clothing with metal zippers, snaps, or underwires, as metal can block the view of the scanner. You may be asked to change into a hospital gown.

Step-by-Step: What to Expect During the Procedure

Knowing what happens during the appointment can help reduce any worries you have about the scan. Here is a typical timeline of a PET scan appointment.

1. Arrival and Injection (Wait Time: ~60 Minutes)

When you arrive, a nurse or technologist will check your blood sugar level. If it is within the acceptable range, they will insert a small IV line into a vein in your arm or hand.

They will inject the radioactive tracer. You will not feel anything different when this happens, no dizziness or sleepiness. After the injection, you must wait for about 60 minutes while your body absorbs the tracer.

During this waiting period, you need to rest quietly. You should avoid reading, looking at your phone, or talking, as brain activity can affect where the tracer goes. You will simply relax in a reclining chair.

2. The Scan (Scan Time: ~30 to 45 Minutes)

Once the waiting period is over, you will move to the scanning room. You will lie down on a narrow table. The technologist will position you comfortably, often using pillows or straps to help you stay still.

The table will slide slowly into the large, doughnut-shaped scanner. The machine is quiet compared to an MRI, but you may hear hums or clicks. You must lie very still. If you move, the images will be blurry.

The scan itself takes about 30 to 45 minutes, depending on which part of the body is being examined. The technologist will be in the next room watching you through a window and can hear you if you speak or need assistance.

3. After the Scan

Once the scan is complete, the technologist will check the images to make sure they are clear. If they are good, you can slide off the table and leave. The radioactive tracer does not stay in your body long. It decays naturally and loses its radioactivity over a few hours.

You should drink plenty of fluids for the rest of the day to help flush the remaining tracer out of your system through your urine. You can go back to your normal diet and activities immediately, unless your doctor tells you otherwise.

Safety and Risks

PET scans are considered very safe diagnostic procedures, but like all medical tests, there are a few things to keep in mind regarding safety.

Radiation Exposure

A PET scan involves exposure to ionizing radiation. The amount is small—roughly equivalent to the amount of natural background radiation a person receives over several years. For most patients, the benefit of an accurate diagnosis far outweighs the low risk associated with this radiation. However, doctors generally try to limit the number of CT and PET scans a patient receives over their lifetime.

Allergic Reactions

Allergic reactions to the radioactive tracer are extremely rare and usually mild. If a reaction does occur, it might involve temporary swelling or redness at the injection site. There are no side effects from the tracer itself; you will not feel "radioactive" or glow.

Pregnancy and Breastfeeding

If you are pregnant or think you might be pregnant, tell your doctor immediately. Radiation can be harmful to a developing baby. If you are breastfeeding, you may need to pump and discard breast milk for a specific time after the scan to avoid passing the tracer to your baby.

Claustrophobia

The PET scanner is a tunnel-shaped machine. If you are afraid of tight spaces, let your doctor know beforehand. While the tunnel is wider than an MRI machine, some people still feel anxious. Your doctor may prescribe a mild sedative to help you relax during the scan.

Reviewing the Results

You will not get your results immediately. A specialist doctor called a radiologist, who is trained to interpret these images, will analyze your scan. They will write a detailed report and send it to the doctor who ordered the test.

This process usually takes 24 to 48 hours. Your doctor will then schedule a follow-up appointment or call you to discuss the findings.

The results will usually describe "hot spots" and "cold spots."

• Hot spots: Areas where the tracer collected in large amounts. This indicates high chemical activity. In cancer studies, this often points to the presence of a tumor. In heart studies, it shows healthy tissue.
• Cold spots: Areas with less tracer. In the heart, this might indicate scar tissue from a heart attack. In the brain, it might indicate areas of lower function associated with certain conditions.

Why Prior Authorization Matters

If you are enrolled in a Medicare Advantage plan, one of the most important steps before getting a PET scan is ensuring "prior authorization" is in place.

Prior authorization is a process where your doctor contacts your health plan to get approval before the service is performed. The plan reviews the request to ensure the PET scan is medically necessary for your condition.

If you skip this step: If your plan requires prior authorization and you get the scan without it, the plan may deny the claim. This means you could be responsible for the full cost of the scan, which can range from $3,000 to $6,000 or more.

Always check with your doctor’s office that they have this approval number before you go to your appointment.

Summary: A Checklist for Beneficiaries

To ensure your PET scan goes smoothly and you reduce your costs, use this simple checklist:

1. Check Medical Necessity: Ask your doctor to confirm that the test is medically necessary and covered by Medicare guidelines.
2. Verify Location: Ensure the imaging center or hospital accepts Medicare (or is in your plan's network if you have Medicare Advantage).
3. Confirm Approval: If you have a Medicare Advantage plan, confirm that prior authorization has been approved.
4. Review Costs: Check your deductible status. If you haven't met your annual deductible, be prepared to pay that amount plus your coinsurance or copay.
5. Prepare: Follow all diet and fasting instructions strictly to avoid needing a repeat scan.

How Wellcare Helps

Navigating your Medicare benefits and medical procedures doesn’t have to be complicated. Wellcare is committed to making healthcare simple, personal, and accessible—helping you get the most out of your coverage. Our Medicare Advantage plans offer benefits that go beyond what Original Medicare provides, supporting your whole health, from physical and emotional wellness to financial peace of mind.

With Wellcare, you have a partner to help you coordinate care, find the right specialists, and understand your costs, including required referrals or prior authorizations for scans like PET procedures. Our knowledgeable member services team can answer your questions, clarify your benefits, and provide local support for everyday needs.

By understanding how Medicare covers these advanced imaging tests, you can focus less on the paperwork and more on what matters most: getting the answers you need for your health journey. Whether you are investigating a new symptom or monitoring an existing condition, a PET scan is a powerful tool that helps your healthcare team create the best possible plan for you.

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