Medicare Part B Excess Charges: Balance Billing Rules
September 8, 2026
What Are Medicare Part B Excess Charges?
Medicare Part B excess charges, also called balance billing, are the extra amount a doctor can bill you above the Medicare-approved amount for a covered service. Medicare Part B is the portion of Original Medicare that pays for outpatient care, physician visits, preventive screenings, and durable medical equipment. Federal law caps this extra charge at 15% above the Medicare-approved amount, and it only applies when your provider does not accept full Medicare assignment. Most doctors accept assignment, so this charge never shows up on their bills. Below is who can charge it, how much it can add to a bill, and how a Medigap plan can cover it in full.
Quick Answer
A Medicare Part B excess charge is an extra fee, capped at 15% above the Medicare-approved amount, that a non-participating provider can bill you for a covered service. Only providers who don't accept Medicare assignment can charge it, and Medigap Plan F or Plan G pays it in full. If your provider accepts assignment, which most do, you will not see this charge.
Who Can Charge You an Excess Fee
Whether you can be balance billed depends on your provider's relationship with Medicare. Assignment is an agreement in which a provider accepts the Medicare-approved amount as full payment for a covered service and bills Medicare directly. Providers fall into three categories:
- Participating providers accept assignment on every claim and cannot bill you more than your standard 20% coinsurance.
- Non-participating providers decide case by case whether to accept assignment. When they don't, they can add up to the 15% limiting charge on top of the Medicare-approved amount.
- Opt-out providers have left the Medicare program entirely. They set their own rates through a private contract with you, and Medicare pays nothing toward the visit, so no 15% cap applies at all.
According to Medicare.gov, the large majority of doctors and other providers who bill Medicare are participating providers, which is why most people never encounter an excess charge.
Provider Billing Types Compared
| Feature | Accepts Assignment | Maximum You Can Be Billed |
|---|---|---|
| Participating provider | Yes, on all claims | Your standard 20% coinsurance only |
| Non-participating provider | Optional, case by case | Up to 15% above the Medicare-approved amount |
| Opt-out provider | No, left Medicare entirely | Whatever the private contract states, no federal cap |
Which States Limit Excess Charges
State insurance law can override the federal 15% limiting charge in some places. A group of states, generally cited as including Connecticut, Massachusetts, Minnesota, New York, Ohio, Pennsylvania, Rhode Island, and Vermont, restrict or prohibit provider balance billing for Medicare patients beyond the approved amount. Rules and enforcement vary by state, so confirm the current requirement with your state insurance department rather than assuming you're automatically protected.
How Medigap Plan F and Plan G Cover Excess Charges
Among the ten standardized Medigap plans sold in most states, only Medigap Plan F and Medigap Plan G include the Part B excess charge benefit, which pays the full 15% overage so you owe nothing extra. Medigap Plan F is not available to anyone who became eligible for Medicare on or after January 1, 2020, under federal rules that phased it out for new enrollees. Plan G remains open to new enrollees and is the more common choice for excess charge protection today. If you're weighing Medicare Advantage vs. Medigap for chronic conditions, keep in mind that excess charge protection is a Medigap-only feature; it does not apply to Medicare Advantage plans, which use their own network and cost-sharing rules instead.
How This Interacts With Medicaid, VA, and Social Security
If you have both Medicare and Medicaid, providers generally cannot bill you for the difference between what Medicare and Medicaid pay; see Medicare and Medicaid and dual-eligible special needs plans for how the two programs coordinate. Veterans who use both Medicare and VA health benefits typically avoid excess charges at VA facilities, since VA providers bill the VA directly rather than Medicare; read more in Medicare and veterans benefits. Your Part B premium, which is unrelated to excess charges, is usually deducted from your Social Security payment; see Medicare and Social Security for how that deduction works. If you're still deciding when to start Part Bdelaying Part B without a penalty may be worth reviewing if you have qualifying employer coverage.
Action Checklist
- Ask your provider's office directly whether they accept Medicare assignment before you schedule care
- Review your Medicare Summary Notice for any charge above the Medicare-approved amount
- Check whether your Medigap plan is Plan F or Plan G, the only plans that cover excess charges
- Confirm your state's balance billing rules with your state insurance department
- Get the terms in writing before accepting care from an opt-out provider
Opt-Out Providers Have No Cap
The 15% limiting charge only applies to non-participating providers still enrolled in Medicare. Providers who have formally opted out of Medicare are not bound by this cap and can charge whatever their private contract states, so ask about costs before you receive care.
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Frequently Asked Questions
Yes, for providers still enrolled in Medicare. Participating providers can only bill your standard coinsurance, and non-participating providers can add up to 15% above the Medicare-approved amount. Providers who have opted out of Medicare entirely are not bound by this limit.
No. Medicare Advantage plans set their own provider networks and cost-sharing rules rather than using the federal 15% limiting charge that applies to Original Medicare. What you owe for out-of-network care depends on your specific plan's terms, so check your plan documents.
Only Medigap Plan F and Medigap Plan G include the Part B excess charge benefit among the standardized plans. Check your policy's benefit chart or call your carrier to confirm which letter plan you have.
Generally no. Providers who serve beneficiaries with both Medicare and Medicaid typically must accept the combined Medicare and Medicaid payment as payment in full. See Medicare and Medicaid for more on how the two programs coordinate.