What Are Medicare Part B Excess Charges?

What is a Medicare Part B excess charge?

A Part B excess charge is the extra amount a non-participating provider is allowed to bill you above the Medicare-approved amount for a covered service. In most cases, this extra amount cannot be more than 15% above the Medicare-approved amount. That cap is officially called the limiting charge.

Excess charges are billed on top of your normal Part B costs. After you meet your annual deductible, Medicare generally pays 80% of the approved amount and you pay the 20% coinsurance. If a provider also adds an excess charge, that amount is billed to you in addition to your 20% share.

Importantly, excess charges only come up in a narrow situation: a provider who has not agreed to accept Medicare assignment. They do not apply to assigned claims or to most participating providers.

The limiting charge: how much can a doctor charge above Medicare's amount?

Federal rules limit how much a non-participating provider can charge, so the 15% cap is not a loophole for unlimited billing. Here is how the numbers work behind the scenes.

Medicare pays non-participating physicians 95% of the participating fee schedule amount, meaning non-par providers are paid 5% less than participating ones. The limiting charge is then set at 115% of that lower non-par amount. Because 115% of 95% equals roughly 109.25%, the most a beneficiary can be charged works out to the participating fee schedule amount times 1.0925.

In plain terms: the headline rule is 'up to 15% above the Medicare-approved amount,' but compared to the full participating fee schedule, the real-world ceiling is about 9.25% more. You are never responsible for any billed amount above the limiting charge for a covered service.

• Limiting charge = 115% of the non-participating fee schedule amount
• Non-participating payment = 95% of the participating fee schedule amount
• Maximum you can be billed = participating fee schedule amount x 1.0925 (about 109.25%)
• You owe nothing above the limiting charge for a covered service

Participating, non-participating, and opt-out providers

Whether you face an excess charge depends entirely on how your provider relates to Medicare. There are three categories.

• Participating providers accept assignment on all Medicare claims. They accept the Medicare-approved amount as full payment and can bill you only the deductible and coinsurance. No excess charges.
• Non-participating providers may choose whether to accept assignment claim by claim. When they do not accept assignment, they can add an excess charge up to the limiting charge.
• Opt-out providers have formally left Medicare and treat you under a private contract. Medicare will not pay for these services, and the limiting charge does not apply, so there is no cap on what they bill. The one exception: if an opt-out provider furnishes emergency or urgent care to a beneficiary who has not already signed a private contract with that provider, they may not charge more than a non-participating provider would (the limiting charge).

How to avoid Part B excess charges

Excess charges are avoidable. The simplest protection is to use providers who accept Medicare assignment, since assigned claims cannot include an excess charge.

• Ask before your appointment whether the provider accepts Medicare assignment; this is the single most reliable step.
• Use Medicare's care-finder tools, or call the office directly, to confirm participation status before scheduling.
• Consider a Medigap plan that covers excess charges if you see specialists who may not accept assignment.
• Know your state rules: eight states require providers to accept assignment, eliminating excess charges entirely.
• Be cautious with opt-out providers using private contracts, where the limiting charge does not protect you.

States that ban Part B excess charges

Eight states prohibit Part B excess charges by requiring providers to accept assignment. If you live in one of these states, you generally will not be billed an excess charge for covered services received in your home state. (This list comes from a third-party Medicare educational source, not a primary CMS page, so confirm your state's current rules if it matters to you.)

The eight states are: Connecticut, Massachusetts, Minnesota, New York, Ohio, Pennsylvania, Rhode Island, and Vermont. Note that some states have nuances (for example, protections may apply only to care received in-state), so verify with your state insurance department.

Which Medigap plans cover excess charges?

Medicare Supplement (Medigap) policies are sold by private insurers and standardized by letter. Two Medigap plans cover Part B excess charges in full: Plan G and Plan F.

Plan F is only available to people who were eligible for Medicare before January 1, 2020. Newer enrollees can get the same excess-charge protection through Plan G. These plans cover excess charges because that benefit is built into their standardized benefit set; most other lettered plans do not include it. Coverage details and premiums vary by insurer and location, so compare specific policies before buying.

How excess charges fit with your other 2026 Part B costs

Excess charges, when they apply, sit on top of your standard Part B costs rather than replacing them. For 2026, the standard Part B premium is $202.90 per month and the annual Part B deductible is $283. After you meet the deductible, you generally pay 20% coinsurance of the Medicare-approved amount.

So in a worst case with a non-participating, non-assigned provider, you could owe your 20% coinsurance plus an excess charge of up to the limiting charge. For most people who use assignment-accepting providers, the excess charge is simply zero.