What Medicare Pays for a CT Scan and What You'll Owe

The Medicare-approved amount is what Medicare decides a CT scan is worth, but it's not what you pay

The Medicare-approved amount (also called the allowable amount) is the maximum price Medicare will pay for a CT scan. It varies by location, type of CT scan, and whether the scan looks at one body part or multiple areas. Medicare sets these amounts based on what providers in your region typically charge, not on what any single hospital or imaging center actually bills.

This matters because your out-of-pocket cost depends on this approved amount, not on the provider's full bill. If a facility bills $2,000 but Medicare's approved amount is $800, you won't owe the difference — but you also won't pay based on the full $2,000. The approved amount is the starting point for calculating what Medicare covers and what you owe.

The approved amount changes yearly, and Medicare publishes these amounts in a database called the Physician Fee Schedule. You can look up what Medicare approves for a specific scan in your area, though the numbers are technical and require knowing the exact procedure code.

Key Takeaways

The Medicare-approved amount is set by Medicare, not by the hospital or imaging center, and varies by location and type of scan.
You are responsible for 20% of the approved amount after you meet your deductible; the facility cannot bill you for the difference between their charge and Medicare's approved amount.
The approved amount is published in Medicare's Physician Fee Schedule, which you can search by procedure code and ZIP code.
Your actual cost depends on whether you have Original Medicare or Medicare Advantage, and whether the facility is in-network for your plan.

How the approved amount affects what you pay

Under Original Medicare (Part A and Part B), you pay 20% of the approved amount after you meet your annual Part B deductible. If the approved amount is $800, you pay $160 (20% of $800) once your deductible is satisfied. The facility must accept the approved amount as payment in full — they cannot bill you for any difference between what they charged and what Medicare approved.

This protection is called assignment. When a provider accepts assignment, they agree to take Medicare's approved amount as full payment for that service. Most imaging centers and hospitals do accept assignment for CT scans, but it is worth confirming before your scan.

If you have a Medicare Advantage plan (Part C), your out-of-pocket cost works differently. Your plan sets its own approved amounts, which may be higher or lower than Original Medicare's. You typically pay a copay or coinsurance based on your plan's terms, not based on Medicare's approved amount. Check your plan documents or call your plan to find out what you'll owe for a CT scan.

Where to find the approved amount for your scan

Medicare publishes the Physician Fee Schedule on its website, updated each January. You can search by procedure code (called a CPT code) and your ZIP code to see what Medicare approves in your area. CT scans have different codes depending on what is being scanned — a chest CT, abdominal CT, and head CT each have their own code.

The easiest way to find your specific approved amount is to call the imaging center where you are scheduled and ask them directly. They can tell you the CPT code for your scan and what Medicare's approved amount is in your location. Many facilities have this information readily available and can give you an estimate of your out-of-pocket cost over the phone.

You can also call Medicare directly at 1-800-MEDICARE to ask about the approved amount for a specific scan in your area. Have your ZIP code and the type of scan ready when you call.

Why the approved amount varies by location

Medicare adjusts approved amounts based on regional differences in the cost of living, provider overhead, and local market rates. A CT scan in a rural area may have a lower approved amount than the same scan in a major city. This is why two people in different states might have different out-of-pocket costs for identical scans.

The approved amount also reflects whether the scan is done at a hospital outpatient department or at an independent imaging center. Hospital-based CT scans often have higher approved amounts than the same scan at a freestanding facility, because hospitals have higher overhead costs.

What happens if the facility charges more than the approved amount

If a provider accepts assignment, they cannot bill you for any amount above Medicare's approved amount. This is federal law. If they do bill you for the difference, you can file a complaint with Medicare or your state's insurance commissioner.

If a provider does not accept assignment (which is rare for CT scans), they can charge up to 15% more than Medicare's approved amount. This is called balance billing. Before your scan, confirm that the facility accepts assignment so you know you won't face unexpected bills.

Deductibles and how they affect your CT scan cost

Your Part B deductible applies to CT scans. Once you meet your deductible in a calendar year, you pay 20% of the approved amount for the rest of that year. If you have not met your deductible yet, you pay the full approved amount until you do, then 20% after that.

If you have already met your deductible earlier in the year — for example, through other doctor visits or tests — you will only owe 20% of the approved amount for your CT scan. If you have not met it yet, ask the imaging center what the approved amount is so you can estimate your total cost.

Frequently Asked Questions

Can I find out the approved amount before I schedule my CT scan?

Yes. Call the imaging center and ask for the CPT code of your scan and the Medicare-approved amount in your area. You can also search the Physician Fee Schedule yourself on Medicare's website, though you need to know the exact procedure code. Having this number before your appointment helps you budget for your out-of-pocket cost.

Does the approved amount change if my doctor orders a more detailed scan?

Yes. A standard CT scan and a CT scan with contrast (dye injected into your vein) have different CPT codes and different approved amounts. A scan of one body part costs less than a scan of multiple areas. Ask your doctor which type you need so you can look up the correct approved amount.

What if I have both Original Medicare and a Medigap plan?

Your Medigap plan may cover some or all of the 20% you owe after Medicare pays its share. Check your Medigap plan documents to see what it covers for imaging services. Many Medigap plans cover the full 20% coinsurance, which means you pay nothing out of pocket for the CT scan.

Is the approved amount the same everywhere in my state?

No. Medicare sets approved amounts by ZIP code or region, not by state. Two cities in the same state can have different approved amounts for the same CT scan. This is why location matters when you are estimating your cost.

What should I do if I receive a bill for more than 20% of the approved amount?

Contact the imaging center's billing department and ask why you were billed more than your 20% coinsurance. If they accepted assignment, they should not have billed you for the difference. If you believe you were billed incorrectly, you can file a complaint with Medicare at 1-800-MEDICARE or with your state's insurance commissioner.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.