Medicare covers CT scans, but only when your doctor orders one for a medical reason — not for screening or routine check-ups
Medicare Part B covers the cost of a CT scan if your doctor believes it is medically necessary to diagnose or treat a condition. The program pays 80% of the approved amount after you meet your annual Part B deductible. You pay the remaining 20%, plus any difference between what the facility charges and what Medicare allows — a gap called balance billing.
The key word is "medically necessary." Medicare will not cover a CT scan ordered for screening purposes — for example, a low-dose lung CT to check for cancer in someone without symptoms, or a heart scan to look for early disease. Your doctor must document a specific symptom, injury, or condition that requires imaging to diagnose or monitor.
Where you have the scan done affects what you pay. A hospital outpatient department typically costs more than a freestanding imaging center, even for the same scan, because hospitals charge a facility fee. Medicare's payment reflects this difference, but your 20% coinsurance is calculated on the higher hospital amount.
Key Takeaways
- Medicare Part B covers CT scans when ordered by your doctor for a medical reason, and you pay 20% of the approved cost after meeting your deductible.
- Screening CT scans — ordered when you have no symptoms — are not covered, even if your doctor recommends one for prevention.
- Hospital outpatient CT scans cost more than the same scan at an imaging center, and your coinsurance is based on the higher hospital fee.
- You can ask your doctor's office to request a pre-authorization from Medicare before the scan to confirm coverage and avoid surprise bills.
- Medigap or Medicare Advantage plans may cover some or all of your coinsurance, depending on your plan.
When Medicare Part B covers a CT scan
Medicare Part B pays for a CT scan when your doctor orders it to evaluate a symptom or condition you currently have. Common examples include a CT of the abdomen to investigate abdominal pain, a CT of the head to rule out stroke after a fall, or a CT of the chest to follow up on an abnormal chest X-ray. The scan must be ordered by a physician, physician assistant, or nurse practitioner — not requested by you alone.
The scan must also be performed at a facility that accepts Medicare. Most hospitals and imaging centers do, but some private or specialty clinics may not. If you are unsure whether a facility is in-network with Medicare, ask the facility directly or call Medicare at 1-800-MEDICARE before scheduling.
Pre-authorization is not required by Medicare for most CT scans, but your doctor's office can request one anyway. This step takes a few days and confirms in writing that Medicare will cover the scan. It does not may provide you will owe nothing — you still pay your coinsurance — but it prevents the facility from billing you for the entire cost if Medicare denies the claim later.
When Medicare does not cover a CT scan
Medicare Part B does not cover screening CT scans. A screening scan is one ordered to look for disease in someone without symptoms. Examples include a low-dose CT of the lungs to screen for lung cancer in a current or former smoker, a CT angiography to screen for coronary artery disease in someone with no chest pain, or an abdominal CT to screen for pancreatic cancer in someone with no abdominal symptoms.
Some screening tests are covered under Medicare Part B preventive benefits — such as a one-time abdominal ultrasound for people at risk of abdominal aortic aneurysm — but CT scans for screening are generally not. If your doctor recommends a screening CT, ask whether it is covered before you have it done. If it is not, you will owe the full cost unless you have supplemental coverage.
Medicare also does not cover CT scans ordered for non-medical reasons, such as for legal proceedings, employment physicals, or insurance underwriting. If a CT is needed for these purposes, you pay out of pocket.
What you pay for a covered CT scan
Your cost depends on whether you have met your Part B deductible for the year and where the scan is performed. For 2024, the Part B deductible is $240 per year. Once you meet it, you pay 20% of Medicare's approved amount for the scan.
Medicare's approved amount varies by location and facility type. A CT scan at a hospital outpatient department might have an approved amount of $1,200, while the same scan at an imaging center might be $600. Your 20% coinsurance is calculated on the approved amount for that specific facility, so you would pay $240 at the hospital and $120 at the imaging center.
If the facility charges more than Medicare's approved amount, you may be billed for the difference — balance billing. Facilities that accept Medicare assignment agree not to balance-bill you, but some do not accept assignment. Before your scan, ask the facility whether they accept Medicare assignment. If they do not, ask for an estimate of what you might owe beyond your coinsurance.
| Scenario | Your Cost |
|---|---|
| You have not met your $240 Part B deductible | You pay the full deductible first, then 20% of the approved amount for the scan |
| You have met your deductible; scan at imaging center with $600 approved amount | $120 (20% of $600) |
| You have met your deductible; scan at hospital with $1,200 approved amount | $240 (20% of $1,200), plus any balance billing if the facility does not accept assignment |
| Screening CT scan (not medically necessary) | You owe the full cost; Medicare does not pay |
How supplemental coverage affects your CT scan costs
If you have a Medigap policy, it may cover some or all of your 20% coinsurance for a CT scan. Medigap plans vary — some cover 100% of coinsurance, others cover a percentage, and some cover nothing for imaging. Check your policy documents or call your Medigap insurer to confirm what your plan covers for CT scans.
If you have a Medicare Advantage plan (Part C), your coverage and costs work differently. Most Advantage plans cover CT scans when medically necessary, but your coinsurance may be lower than 20% — often $0 to $150 per scan, depending on your plan. Some Advantage plans require a copay instead of coinsurance. Check your plan's summary of benefits or call the plan directly to learn your specific cost for a CT scan.
Neither Medigap nor Medicare Advantage covers screening CT scans that Medicare Part B does not cover. If your doctor recommends a screening scan and it is not covered by Medicare, supplemental coverage will not pay for it either.
How to reduce your out-of-pocket costs
Ask your doctor whether the CT scan is truly necessary or whether another imaging test — such as an ultrasound or MRI — might work instead. Some tests cost less than others, and Medicare's approved amounts differ. Your doctor may be able to order a less expensive alternative that still answers the clinical question.
Request a pre-authorization from Medicare before your scan. Your doctor's office can submit this request, and Medicare will confirm in writing whether the scan is covered. This step does not reduce your coinsurance, but it prevents a denial after the scan is done.
Ask the facility for an estimate of your out-of-pocket cost before the scan. Provide the facility with your Medicare number and ask them to calculate what you will owe based on your deductible status and their approved amount. If the cost is higher than you expected, ask whether the scan can be done at a lower-cost facility, such as an imaging center instead of a hospital.
If you do not have supplemental coverage and your coinsurance is a financial hardship, ask the facility's financial counselor about payment plans or discounts for uninsured or underinsured patients. Some facilities offer reduced rates if you pay in full before the scan.
Frequently Asked Questions
Will Medicare cover a CT scan my doctor recommends for prevention?
No. Medicare covers CT scans only when ordered to diagnose or treat a current condition. A screening CT ordered for prevention — even if your doctor recommends it — is not covered. Ask your doctor whether the scan is for a symptom or condition you have now, or whether it is for screening purposes.
What if I get a bill from the imaging center after my CT scan?
First, check whether the facility accepted Medicare assignment. If they did, they agreed not to bill you for more than your coinsurance. If you receive a bill for more, contact Medicare at 1-800-MEDICARE to report balance billing. If the facility did not accept assignment, you may owe the difference between what they charged and what Medicare paid.
Does Medicare cover a CT scan at an urgent care or emergency room?
Yes, if the scan is medically necessary. Emergency room and urgent care CT scans are covered the same way as scans at a hospital or imaging center — you pay 20% of the approved amount after your deductible. However, emergency room facilities often charge higher facility fees, so your coinsurance may be higher than at an outpatient imaging center.
Can I get a CT scan covered if I have not met my Part B deductible?
Yes. Medicare will cover the scan, but you will pay your full $240 deductible first, then 20% of the approved amount. Once you meet your deductible in a calendar year, you pay only 20% coinsurance for the rest of that year.
What if my Medicare Advantage plan denies my CT scan?
Contact your plan to ask why it was denied. Common reasons include the scan was deemed not medically necessary, it was ordered by an out-of-network provider, or the facility was out-of-network. You have the right to request an appeal. Your plan must respond to an appeal within 30 days for standard reviews or 72 hours for urgent reviews.