Medicare does cover MRI scans, and it covers CT scans, X-rays, ultrasounds, PET scans, and most other diagnostic imaging on the same terms: a physician treating you for the condition has to order the test, and the facility has to be enrolled in Medicare. Under Original Medicare, you pay 20% of the Medicare-approved amount after meeting the 2026 Part B deductible of $283.1Centers for Medicare & Medicaid Services. 2026 Medicare Parts A and B Premiums and Deductibles Medicare pays the other 80%.2Office of the Law Revision Counsel. 42 USC 1395l – Payment of Benefits
What Has to Be True for Medicare to Pay
Every diagnostic scan needs a written order from the physician actively treating you for the problem being investigated. A doctor who isn’t managing your care for that condition can’t order the test and have Medicare pay for it.3eCFR. 42 CFR 410.32 – Diagnostic X-Ray Tests, Diagnostic Laboratory Tests, and Other Diagnostic Tests: Conditions The order has to include the clinical reason: specific symptoms or a diagnosis code that explains why the imaging is needed.
Medicare then judges the claim against a “reasonable and necessary” standard. If the diagnosis code on the claim doesn’t line up with a recognized indication for the test, or if Medicare treats the test as experimental for your condition, the claim gets denied. Mismatched codes are one of the most common reasons imaging claims come back rejected, so it’s worth confirming with your physician’s office that the order and the diagnosis actually match.
Before the appointment, check two things. First, that your doctor has sent the written order to the imaging facility. Second, that the facility accepts Medicare assignment. Providers who accept assignment agree to take the Medicare-approved amount as full payment. Non-participating providers can charge up to a “limiting charge” of 115% of the non-participating fee schedule, which itself sits at 95% of the standard rate.4Office of the Law Revision Counsel. 42 USC 1395w-4 – Payment for Physicians Services In practice, that works out to roughly 9% more out of your pocket than at an assignment provider.5Centers for Medicare & Medicaid Services (CMS). MA Payment Guide for Out of Network Payments Most imaging centers accept assignment, but confirm it before you show up.
What You’ll Actually Pay for an Outpatient Scan
For an MRI, CT, X-ray, ultrasound, PET, or EKG performed at a doctor’s office, freestanding imaging center, or hospital outpatient department, Part B pays as a diagnostic non-laboratory service. After your $283 deductible for the year, you owe 20% of the Medicare-approved amount for each scan.
Where you go matters. Hospital outpatient departments generally cost more than freestanding imaging centers for the same test. The 2026 national average Medicare-approved amount for a brain MRI without contrast is about $508 at a freestanding center versus $672 at a hospital outpatient department. Your 20% share, roughly $101 versus $134, moves with it.6Medicare.gov. Procedure Price Lookup for Outpatient Services – 70553 The Procedure Price Lookup tool on Medicare.gov lets you compare by facility type before you schedule.
Bills sometimes come in pieces. Every imaging service has a technical component (the equipment, the technologist, the facility) and a professional component (the radiologist who reads the images). At a freestanding center you’ll often see a single combined bill. At a hospital outpatient department, you’re more likely to receive one charge from the hospital and a second from the physician who interpreted the scan. Both are Part B services with the same 20% coinsurance.
Contrast Dye and Tracers
Many scans need contrast or a radioactive tracer, and how those get billed depends on the test. For CT with contrast, standard contrast dye is generally rolled into the procedure payment. For MRI with contrast, the dye is billed separately under its own code, so expect an additional line item. PET scans and other nuclear medicine studies always bill the radiopharmaceutical tracer separately from the scan.7Centers for Medicare & Medicaid Services (CMS). Medicare Claims Processing Manual, Chapter 13 – Radiology Services and Other Diagnostic Procedures Those extra charges are still Part B at 20%, but they can be a surprise if you were expecting one bill for one test.
When Imaging Costs You Nothing
A short list of imaging tests count as preventive screenings rather than diagnostic tests. If your provider accepts assignment, Medicare covers them with no deductible and no coinsurance.8Medicare.gov. Preventive and Screening Services The distinction is real money: a diagnostic mammogram to investigate a lump costs you 20% after the deductible, while a routine screening mammogram costs nothing.
- Screening mammograms: one baseline between ages 35 and 39, then one every 12 months for women 40 and older.9Medicare.gov. Mammograms
- Lung cancer screening: one low-dose CT per year if you’re 50 to 77, currently smoke or quit within the last 15 years, and have at least a 20 pack-year history. A counseling visit is required before the first screening.10Medicare.gov. Lung Cancer Screenings
- Bone mass measurements: one DEXA scan every 24 months, or more often when medically justified, for people meeting the risk criteria.11Medicare.gov. Bone Mass Measurements
- CT colonography as part of colorectal cancer screening for eligible individuals.
Two things collapse the free benefit. If the provider doesn’t accept assignment, standard cost-sharing kicks back in. And if a screening leads to a diagnostic follow-up in the same visit, say the radiologist sees something suspicious and orders additional views, that second test is billed under regular Part B rules with the deductible and 20% coinsurance.
Inpatient Imaging and the Observation Trap
If you’ve been formally admitted to a hospital as an inpatient, imaging ordered during your stay is bundled into the hospital’s Part A payment for the admission.12Social Security Administration. Social Security Act 1812 – Scope of Benefits You won’t see line-item charges for each scan. You pay the Part A inpatient deductible for the admission, and the hospital absorbs the imaging costs.
Being in a hospital bed overnight is not the same as being admitted. If you don’t have a physician’s inpatient order, you’re an outpatient under “observation status,” and Part A pays nothing. Part B covers your doctor and the hospital’s outpatient services, including imaging, at the usual 20% coinsurance per service.13Medicare.gov. Inpatient or Outpatient Hospital Status Affects Your Costs Observation days also don’t count toward the three consecutive inpatient days Medicare requires before it will cover a skilled nursing facility stay. Ask your care team directly which status you’re in.
When a Provider Warns You Medicare May Not Pay
If your provider thinks Medicare is unlikely to cover a particular scan, they have to give you an Advance Beneficiary Notice (ABN) before performing it.14Centers for Medicare & Medicaid Services (CMS). Advance Beneficiary Notice of Non-coverage (ABN) Form Instructions The notice explains why coverage may be denied and offers three choices: proceed and pay yourself if Medicare declines, proceed and ask Medicare for a formal decision so you can appeal, or decline the test.
The ABN has to reach you early enough to think about it. It can’t be handed to you on the imaging table. Common triggers are diagnoses that don’t match the test, tests ordered more often than Medicare allows, and services Medicare considers experimental. Emergencies don’t require an ABN. If a provider performs a non-covered test without giving you a proper ABN first, that’s a billing error, and you generally can’t be held responsible for the charge.
Cutting the 20%: Medigap and Medicare Advantage
Original Medicare has no annual out-of-pocket cap, so on Original Medicare alone, the 20% keeps coming with every scan. Two paths reduce that exposure.
A Medigap (Medicare Supplement) policy pays some or all of the Part B coinsurance left over after Medicare. Most Medigap plan letters cover the full 20% for a covered scan, dropping your share to zero once the plan pays. A couple of plans pay a partial share with an annual out-of-pocket ceiling that then triggers full coverage for the rest of the year.15Medicare.gov. Compare Medigap Plan Benefits
Medicare Advantage (Part C) replaces Original Medicare’s cost-sharing with the plan’s own copays, coinsurance, and deductibles. Some plans charge a flat copay per scan instead of a percentage. The structural benefit is an annual out-of-pocket maximum: hit it, and the plan pays 100% of your Part A and Part B services for the rest of the year.16Medicare.gov. Understanding Medicare Advantage Plans The trade-off is prior authorization. Many Advantage plans require approval before an MRI, CT, or other advanced imaging, and denials happen even when the test would meet Medicare’s standard coverage criteria. Starting in 2026, plans must decide standard prior authorization requests within 7 calendar days and give a specific reason for any denial. If your plan denies, it has to tell you how to appeal, and if it upholds its own denial, the case moves automatically to an independent reviewer.
If Medicare Denies Your Imaging
After your scan, the provider bills Medicare directly. You’ll see the outcome on a Medicare Summary Notice showing what was billed, what Medicare approved, what Medicare paid, and what you owe.17Medicare.gov. Medicare Summary Notice Read every notice against what actually happened. Wrong diagnosis codes and duplicate charges on imaging claims are common enough to be worth catching early.
If Medicare denies coverage and you believe the test was medically necessary, you have 120 days from the date you receive the initial determination to file an appeal. Medicare presumes you received the notice five days after its date, so that’s when your clock effectively starts.18Centers for Medicare & Medicaid Services. First Level Appeal: Redetermination by a Medicare Contractor The first step is a redetermination by the Medicare contractor that processed the original claim, with additional levels of review after that if you lose. Most imaging denials that get reversed are reversed at the first or second level because the real problem was incomplete documentation. A detailed letter of medical necessity from your physician, submitted with the appeal, significantly improves your odds.