How long does it take to get approval for an MRI from Medicare?

Original Medicare does not require prior authorization for an MRI, but if you have a Medicare Advantage (Part C) plan, approval typically takes up to 7 calendar days for standard requests or 72 hours for urgent/expedited requests.

Original Medicare vs. Medicare Advantage

• Original Medicare (Parts A & B): Prior authorization is rarely required. If your doctor who accepts Medicare orders a medically necessary MRI, Medicare covers its share (typically 80%) without a formal pre-approval wait time.
• Medicare Advantage Plans: Private insurance companies manage these plans and commonly require prior authorization for imaging services like MRIs. Under federal rules, standard prior authorization decisions must be made within 7 calendar days, and urgent requests within 72 hours.

Factors That Can Delay Approval

• Incomplete Documentation: If the insurance provider needs more clinical notes, symptom history, or proof that conservative treatments failed, the review window can be extended.
• Non-Urgent vs. Urgent Status: Routine scans follow the 7-day standard timeline, whereas life-or-health-threatening situations qualify for the 72-hour expedited process.

Medicare does not limit the total number of MRI scans you can have, as long as each scan is determined to be medically necessary by your doctor to diagnose or treat a health condition.

Coverage Rules

• Medical Necessity: Medicare covers an MRI as a diagnostic tool, but it will not pay for routine, preventative, or elective scans requested without a clinical reason.
• Doctor's Order: A doctor or authorized health provider who accepts Medicare must order the test.
• Approved Facility: The testing facility or hospital must accept Medicare and be accredited for advanced diagnostic imaging.

Costs

• Inpatient (Part A): If you are admitted to a hospital, Part A covers 100% of the costs after you pay your inpatient deductible for the first 60 days.
• Outpatient (Part B): If you get an MRI as an outpatient, Part B covers 80% of the Medicare-approved amount after you meet your annual Part B deductible. You pay the remaining 20% coinsurance, unless you have supplemental insurance (Medigap) or a Medicare Advantage plan that alters cost-sharing.

Medicare or a Medicare Advantage plan may deny an MRI if they determine the scan is not medically necessary or if specific administrative requirements are not met.

Common Reasons for Denial

• Lack of Medical Necessity: Medicare requires a clear clinical reason to diagnose or treat a specific medical problem. Routine wellness checks, whole-body scans without symptoms, or repeat scans without changing conditions are not covered.
• Skipped Conservative Treatments: For conditions like lower back or joint pain, insurers often require proof that simpler, cheaper treatments—such as physical therapy, anti-inflammatory medications, or X-rays—failed over a period of several weeks before approving an MRI.
• Missing Prior Authorization: Many plans (especially Medicare Advantage) require your doctor to get advance approval before you receive the scan. If your doctor's office misses deadlines or fails to submit the request properly, the service will be denied.
• Insufficient Documentation: If the clinical notes do not explicitly detail your progressive symptoms, duration of pain, or risk factors, the insurer may rule that the necessity was not established.
• Provider or Safety Restrictions: Original Medicare has specific rules, such as contraindications for certain implanted devices like older pacemakers. Additionally, the imaging facility must be Medicare-approved and accredited.
• Step Therapy/Alternative Imaging: Insurers may deny an MRI if they believe an X-ray or CT scan—which costs significantly less—should be performed first.

What You Can Do

Most users on Reddit agree that denials can frequently be overturned through the appeals process, especially since a high percentage of initial managed-care denials are reversed when extra documentation or a peer-to-peer review is provided.

No, an MRI is not fully covered for free by Medicare, though it is partially covered if it is deemed medically necessary.

Coverage by Medicare Part

• Inpatient (Part A): If you are admitted to a hospital, Medicare Part A covers 100% of the cost for the MRI after you pay your inpatient hospital deductible.
• Outpatient (Part B): If you get an outpatient MRI, Medicare Part B covers 80% of the Medicare-approved amount after you meet your annual Part B deductible. You are responsible for the remaining 20% coinsurance.

Key Requirements

• Medical Necessity: Your doctor must order the MRI to diagnose or treat a specific medical condition. Medicare does not cover routine or elective scans.
• Medicare Acceptance: Both your doctor and the imaging facility must accept Medicare assignment.

Ways to Lower Your Costs

• Medigap: Supplemental insurance plans can help pay the 20% outpatient coinsurance and deductibles.
• Medicare Advantage (Part C): These private plans must offer at least the same benefits as Original Medicare, but copays and network rules vary.

Under Original Medicare, your out-of-pocket cost for a medically necessary outpatient MRI is typically 20% of the Medicare-approved amount, which averages between $60 and $180 per scan. However, your actual cost depends entirely on whether you are an inpatient or outpatient, your specific plan, and where you get the scan.

The cost breakdown across different parts of Medicare includes:

🏥 Outpatient MRI (Medicare Part B)

If you receive your MRI at an imaging center, doctor's office, or hospital outpatient department:

• Annual Deductible: You must first meet the 2026 Part B deductible of $283.
• Coinsurance: Once met, Medicare pays 80%, and you pay a 20% coinsurance.
• Location Matters: Independent, freestanding imaging centers are significantly cheaper than hospital outpatient departments. For a standard outpatient brain MRI (CPT 70553), the average 20% patient share is about $38 at an ambulatory center versus $71 at a hospital outpatient department. Hospital outpatient facilities may also add a separate copay.

🏨 Inpatient MRI (Medicare Part A)

• If the MRI is performed while you are formally admitted to a hospital, it is covered under Medicare Part A.
• After paying the Part A deductible ($1,736 per benefit period in 2026), the MRI is fully covered ($0 out-of-pocket) for the first 60 days of your hospital stay.

🛡️ Supplemental and Advantage Plans

• Medigap (Medicare Supplement): If you have a supplemental policy like Plan G, it will usually pay your 20% coinsurance, bringing your out-of-pocket cost for the scan down to $0 (assuming your Part B deductible has been met).
• Medicare Advantage (Part C): These private insurance plans must cover MRIs, but they use flat copays (typically ranging from $50 to $350) instead of a 20% coinsurance. They also usually require prior authorization before you get the scan.

Note: For Medicare to cover the scan, the MRI must be deemed medically necessary by a Medicare-approved doctor, and the facility performing the scan must accept Medicare. Purely elective or full-body screening scans without clinical reason are not covered. You can check specific estimated costs for your area using the Medicare Procedure Price Lookup tool.