Medicare Part B Excess Charges: What They Are and How the 15% Limit Works

Sources: Medicare.gov: Does your provider accept Medicare as full payment? · Compare Medigap plan benefits

This guide explains what Part B excess charges are, how the 15% limit works, which Medigap plans pay them and how to check whether your doctors accept assignment. We don't show prices or recommend a plan; we explain the rules from Medicare.gov.

What are Medicare Part B excess charges?

Medicare sets a Medicare-approved amount for each covered service. What you pay depends on whether your doctor accepts that amount as full payment (Medicare.gov).

• Doctors who accept assignment agree to take the Medicare-approved amount as full payment for all Medicare-covered Part A and Part B services. They can charge you only the Medicare deductible and coinsurance, and they submit your claim to Medicare.
• Non-participating doctors don't accept assignment for all services, though some accept the Medicare-approved amount case by case. When they don't accept assignment, they can charge more than the Medicare-approved amount. For doctors' services, it can't be more than 15% above the Medicare-approved amount. Medicare calls this the "limiting charge," and the extra amount is the excess charge.
• Opt-out doctors don't work with Medicare. Medicare won't pay for items or services from a provider who opts out, except in emergencies, and you may sign a private contract and pay the doctor directly.

Medicare.gov notes that the limiting charge doesn't apply to every Medicare-covered service, such as some supplies and durable medical equipment (Medicare.gov).

What happens when a doctor doesn't accept assignment

If your doctor, provider or supplier doesn't accept assignment (Medicare.gov):

• You might have to pay the full amount at the time of service.
• They should submit a claim to Medicare for Medicare-covered services, and they can't charge you for submitting it. If they refuse, you can submit your own claim to Medicare.
• They can charge you more than the Medicare-approved amount. For doctors' services, that excess charge can't be more than 15% above the Medicare-approved amount.

You still pay your usual Part B share too: the yearly Part B deductible ($283 in 2026, per CMS) and, after that, usually 20% of the Medicare-approved amount.

Which Medigap plans pay Part B excess charges?

Source: Medicare.gov: Compare Medigap plan benefits

Plans C and F aren't available to people who became eligible for Medicare on or after January 1, 2020. If you were eligible for Medicare before January 1, 2020, you may still be able to buy Plan C or Plan F. To compare Medigap letters on this point, see Plan G vs Plan N, Medicare Supplement Plan G, Medicare Supplement Plan N and high deductible Plan G.

Medicare Advantage plans work differently: they set their own network rules and costs. See What is Medicare Part C?

See how the 15% limit works

Enter a Medicare-approved amount from a bill, an estimate or your Medicare Summary Notice. The calculator shows the most a doctor who doesn't accept assignment can charge for a doctor's service, how big the excess charge could be, and which coverage pays it.

How to check whether a doctor accepts Medicare assignment

Timing matters if you're choosing a Medigap letter

You can apply for a Medigap policy at any time, but timing matters. Your Medigap Open Enrollment Period is a one-time 6-month window that starts the first month you're 65 or older and enrolled in Part B. During it, a company can't turn you down or charge more because of your health, though it may make you wait up to 6 months to cover a pre-existing condition. Outside it, insurers may ask health questions, charge more or turn you down (Medicare.gov). See Medigap Open Enrollment Period, Medicare enrollment dates and turning 65 in Utah.

For the Utah picture across all letters, see Medicare Supplement plans in Utah and What is Medigap?

Considering Medicare Advantage instead?

Excess charges are an Original Medicare and Medigap topic. Medicare Advantage is a different path, and Medigap can't be used with a Medicare Advantage plan. Compare the two coverage styles in Medicare Advantage vs. Medicare Supplement, or use our Original Medicare vs. Medicare Advantage comparison tool. Medicare Advantage changes happen during Open Enrollment and the Medicare Advantage Open Enrollment Period, which are separate from your Medigap window.

How our team helps

We're Boo Insurance Services, a licensed independent Medicare agency in Draper, licensed since 2014. We've helped 1,000+ Utahns with Medicare and have 170+ 5-Star Google Reviews. We meet by phone or video anywhere in Utah, help you think through how your doctors work with Medicare and explain which Medigap letters pay excess charges. You won't pay us a fee. Insurance companies pay us when you enroll, and that doesn't change your plan's benefits, coverage or premium. If we talk about Medicare Advantage or drug plans, Medicare rules require a short Scope of Appointment form first. You decide, with no obligation.

Frequently asked questions

What are Medicare Part B excess charges?

If a doctor doesn't accept Medicare assignment, they can charge more than the Medicare-approved amount. That extra amount is the excess charge. For doctors' services, it can't be more than 15% above the Medicare-approved amount.

How much can a doctor charge above the Medicare-approved amount?

A doctor who doesn't accept assignment can charge more than the Medicare-approved amount. For doctors' services, it can't be more than 15% above the Medicare-approved amount. Medicare calls this the limiting charge. It doesn't apply to every Medicare-covered service, such as some supplies and durable medical equipment.

Which Medigap plans cover Part B excess charges?

Plan F and Plan G pay 100% of Part B excess charges, including the high-deductible versions once the deductible is met. Plans A, B, C, D, K, L, M and N don't. Plans C and F aren't available to people who became eligible for Medicare on or after January 1, 2020.

Do most doctors accept Medicare assignment?

Medicare.gov notes that most doctors, providers and suppliers accept assignment, but always check. You can ask the office or look the doctor up on Medicare.gov.

Does Original Medicare pay excess charges?

No. Original Medicare pays its share of the Medicare-approved amount. If a doctor doesn't accept assignment, you pay the excess charge yourself unless you have a Medigap plan that covers it.

What's the difference between a non-participating doctor and an opt-out doctor?

A non-participating doctor can still bill Medicare and can charge more than the Medicare-approved amount. For doctors' services, it can't be more than 15% above the Medicare-approved amount. An opt-out doctor doesn't work with Medicare, and Medicare won't pay for their services, except in emergencies.

Does Plan N cover Part B excess charges?

No. If a doctor doesn't accept Medicare assignment, they can charge more than the Medicare-approved amount. For doctors' services, that can be up to 15% more, and Plan N doesn't pay that excess charge.

Serving Utah residents. We do not offer every plan available in your area. Currently we represent 9 organizations which offer 58 products in your area. Please contact Medicare.gov or 1-800-MEDICARE to get information on all of your options.

Sources

• Medicare.gov, Does your provider accept Medicare as full payment?
• Medicare.gov, Compare Medigap plan benefits
• Medicare.gov, Find & compare doctors
• Medicare.gov, Choosing a Medigap Policy (CMS Product 02110)
• Medicare.gov, When can I buy a Medigap policy?
• CMS, 2026 Medicare Parts A & B Premiums and Deductibles

Not connected with or endorsed by the United States government or the federal Medicare program. Fores Boo, licensed independent Medicare agent, NPN 17255694, Boo Insurance Services, 61 W 13490 S Ste 201, Draper, UT 84020.

Last updated: October 21, 2026.