Medicare processes more than one billion claims per year. A small percentage of those claims contain errors, duplicate billing, services billed that were never received, wrong billing codes, or charges for services that should have been covered as preventive care. The Medicare Summary Notice is your primary tool for catching these errors, and you have both the right and the process to dispute them. Most people never review their MSN, which means billing errors go unchallenged and are quietly absorbed or affect future coverage decisions.
I tell every client to look at their Medicare Summary Notice when it arrives rather than filing it unopened. Most billing errors are coding mistakes, not fraud, and they are fixable with a quick call to the provider's billing department. The ones that do not get resolved quickly are what 1-800-MEDICARE is for. It takes ten minutes to review a quarterly MSN. The mistakes it catches can cost you real money.
What the Medicare Summary Notice is
The Medicare Summary Notice is a quarterly statement Medicare mails to Original Medicare beneficiaries. It lists all services billed to Medicare on your behalf during the quarter, including the provider name, date of service, service description, Medicare-approved amount, what Medicare paid, and what you may owe. The MSN is not a bill, it is an explanation of what Medicare paid and what cost-sharing was applied. Keep each MSN for review and comparison to any bills you receive from providers.
What to look for when reviewing your MSN
Compare each MSN entry to your actual healthcare calendar. Services you did not receive: a provider may have billed for a service, test, or visit that did not occur. Duplicate entries: the same service billed twice for the same date. Incorrect dates: a service billed on a date you were not at that provider. Upcoding: a more expensive service billed than what was performed (for example, an extended office visit billed when you had a brief visit). Preventive care billed with cost-sharing: if you had a preventive screening, it should show $0 cost to you; if it shows cost-sharing, the billing code may be wrong. Provider you do not recognize: may indicate identity theft or billing fraud.
The dispute process: step one
Contact the provider or supplier directly. Many billing errors result from clerical mistakes, wrong billing codes, or miscommunication between provider and billing staff. Call the provider's billing department, explain the discrepancy, reference the MSN entry date and service, and ask for a corrected claim to be submitted to Medicare. Providers can resubmit claims with corrections within Medicare's timely filing limits. Keep a record of the date, time, person spoken to, and outcome of your call.
The dispute process: step two
If the provider does not resolve the issue or you believe fraud may be involved, call 1-800-MEDICARE. Representatives can look up claim details, explain what was billed, and in some cases flag an issue for review. For suspected fraud, report to the Office of Inspector General Hotline at 1-800-HHS-TIPS. Medicare takes fraud reporting seriously, and reports from beneficiaries have led to significant recoveries.
Got a Medicare bill that does not look right?
Billing disputes are more straightforward than most people expect, and many errors get resolved quickly once you know who to call. I am glad to help you understand what you were charged and whether it is correct.
Book a Free CallFormal appeal rights
You have the right to formally appeal any Medicare claim decision, including a decision about what Medicare paid or did not pay. The first level of appeal for Original Medicare is a Redetermination request submitted to your Medicare Administrative Contractor within 120 days of the initial determination. Appeal levels for Original Medicare mirror those for Medicare Advantage: redetermination, reconsideration by a Qualified Independent Contractor, ALJ hearing, Medicare Appeals Council, and federal court. For most billing disputes, the provider correction or 1-800-MEDICARE resolution is sufficient. The formal appeal process is used when a claim is denied or payment is lower than expected.
Medicare Advantage EOBs versus the MSN
If you have Medicare Advantage, you receive an Explanation of Benefits from your plan rather than an MSN from Medicare. The EOB serves the same function but comes from your private insurer rather than CMS. Review it the same way, look for services you did not receive, duplicate entries, and incorrect cost-sharing. Dispute processes through Advantage plans start with the plan itself rather than 1-800-MEDICARE.
Frequently asked questions