Medicare part b excess charges catch many beneficiaries off guard. These extra costs happen when a doctor does not accept Medicare assignment. In that case, the provider can bill up to 15% above the Medicare-approved amount. That difference comes straight out of your pocket. According to Table of Contents
kff.org/medicare/how-many-physicians-have-opted-out-of-the-medicare-program/”>KFF research, roughly 98% of physicians participate in Medicare and accept assignment on all claims. However, the remaining providers who do not accept assignment can charge you more. For beneficiaries on fixed incomes, even a 15% surcharge on medical bills adds up quickly. Understanding how these charges work — and what protections exist — is essential for anyone enrolled in Original Medicare.
What Are Medicare Part B Excess Charges?
When a doctor accepts Medicare assignment, they agree to accept the Medicare-approved amount as full payment. You pay your 20% coinsurance, and the provider cannot bill you beyond that. Non-participating providers work differently. They can charge up to 15% more than the Medicare-approved amount. This additional cost is the excess charge.
For example, imagine Medicare approves $200 for a service. A non-participating provider can bill up to $230. After your 20% coinsurance on the approved amount, the extra $30 is your responsibility. Medicare does not cover any portion of that excess. Fortunately, federal law caps the overage at 15%. Providers who bill beyond this limiting charge must issue you a refund.
Some doctors opt out of Medicare entirely. These providers have no billing limits at all. As a result, you could owe the full cost of the visit. KFF data from November 2024 shows opt-out rates are highest in the District of Columbia at 2.9%, followed by Alaska at 2.8% and Colorado at 2.3%. Before scheduling any appointment, confirm whether your provider participates in Medicare.
States That Ban Medicare Part B Excess Charges
Eight states have passed laws prohibiting providers from billing excess charges to Medicare beneficiaries. These states are Connecticut, Massachusetts, Minnesota, New York, Ohio, Pennsylvania, Rhode Island, and Vermont. If you live in one of these states, participating and non-participating providers alike must accept the Medicare-approved amount as payment in full.
New York offers an additional layer of protection. State law limits any excess charge to just 5% rather than the federal cap of 15%. Beneficiaries in these eight states typically have lower out-of-pocket costs for Part B services. Keep in mind that this protection only applies within your home state. If you travel and see a provider in a state without these protections, you may still face excess charges.
Residents of the other 42 states and territories should take extra steps to protect themselves. Checking a provider’s Medicare participation status before every visit is a smart habit. You can verify this through Medicare’s Care Compare tool or by calling the provider’s office directly.
How Medigap Plans Protect Against Excess Charges
Medicare Supplement (Medigap) insurance is the most reliable way to shield yourself from medicare part b excess charges. Two plan types cover these costs: Plan F and Plan G. Both pay the full 15% excess charge on your behalf. The key difference is that Plan F also covers the Part B deductible, while Plan G does not.
There is an important eligibility detail. CMS rules prevent anyone newly eligible for Medicare on or after January 1, 2020, from purchasing Plan F. Plan G remains available to all beneficiaries and is now the most popular Medigap option nationwide. Carriers like Mutual of Omaha, Blue Cross Blue Shield, Aetna, and Cigna all offer Plan G in most states. Premiums vary by state, age, and carrier, so comparing quotes is essential.
Medicare Advantage plans from UnitedHealthcare, Humana, and similar carriers handle costs differently. These plans use provider networks. In most cases, you will not face excess charges because network providers have agreed-upon rates. However, seeing an out-of-network provider under a Medicare Advantage PPO plan could result in higher costs. Your local SHIP program offers free counseling to help you compare options.
How to Avoid Medicare Part B Excess Charges
Protecting yourself starts with choosing providers who accept assignment. Ask every provider’s office before scheduling. The phrase you want to hear is “we accept Medicare assignment.” This single step eliminates excess charges entirely. You can also search the Medicare.gov provider directory to check participation status in advance.
If you have Original Medicare without a Medigap plan, consider enrolling during your Medigap Open Enrollment Period. This six-month window begins the month you turn 65 and enroll in Part B. During this period, insurers cannot deny coverage or charge higher premiums based on health conditions. Missing this window can make coverage more expensive or harder to obtain later. Choosing Plan G during open enrollment gives you guaranteed protection against medicare part b excess charges for life.
Finally, keep records of every medical bill. Compare the amount billed against the Medicare Summary Notice you receive. If a provider charged more than 15% above the approved amount, you are owed a refund. Contact the provider first. If they do not comply, report the issue to 1-800-MEDICARE or your state insurance department.
Frequently Asked Questions
How much can a doctor charge above the Medicare-approved amount?
Federal law sets the limiting charge at 15% above the Medicare-approved amount. Non-participating providers cannot exceed this cap. If they do, you have the right to request a refund for the overcharge.
Do all states allow medicare part b excess charges?
No. Eight states ban excess charges entirely: Connecticut, Massachusetts, Minnesota, New York, Ohio, Pennsylvania, Rhode Island, and Vermont. In addition, New York caps any excess at 5% rather than the federal 15% limit.
Does Medicare Advantage protect against medicare part b excess charges?
Medicare Advantage plans use provider networks with pre-negotiated rates. As a result, in-network providers do not bill excess charges. However, out-of-network care under a PPO plan may carry higher cost-sharing that functions similarly to excess charges.
Which Medigap plan is best for avoiding excess charges?
Plan G is the best option for anyone newly eligible for Medicare after January 1, 2020. It covers 100% of Part B excess charges along with most other out-of-pocket costs. Plan F also covers excess charges but is only available to those who became Medicare-eligible before 2020.
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Official Sources & Resources
For verified information on Medicare regulations and consumer protection:
- Medicare.gov (Official Site): medicare.gov
- CMS (Centers for Medicare & Medicaid Services): cms.gov
- NAIC (National Association of Insurance Commissioners): naic.org
- KFF Medicare Research: kff.org/medicare
- Social Security Administration: ssa.gov
Content last reviewed April 2026. If you notice any outdated information, please contact us.