A Medicare Part B excess charge is the extra amount a doctor who does not accept Medicare assignment is allowed to bill you — in many cases no more than 15% above the Medicare-approved amount, a ceiling Medicare calls the limiting charge (Medicare.gov). Florida has not banned them, so if you see a non-participating specialist here, that charge is yours to pay unless your Medicare Supplement policy covers it.
That is the whole answer. What follows is the part almost every article on this gets slightly wrong — because the 15% is not 15% of the number you are thinking of, and the gap it creates between Plan G and Plan N is smaller than the scare stories and larger than zero.
What is a Medicare Part B excess charge?
Every doctor who bills Medicare Part B sits in one of three categories, and the category decides what they can charge you.
Participating providers have signed an agreement to accept assignment on every Medicare claim. Assignment means they accept Medicare’s approved amount as payment in full. Medicare.gov puts the consumer benefit plainly: they “agree to charge you only the Medicare deductible and coinsurance amount,” they bill Medicare directly, and they cannot charge you for submitting the claim. Most doctors are in this group.
Non-participating providers have not signed that agreement but have not left Medicare either. They may accept assignment case by case. When they do not, they can bill you above the approved amount — and that overage is the Part B excess charge.
Opt-out providers have withdrawn from Medicare entirely, for a minimum of two years at a time. Medicare pays nothing for their services except in emergencies, and you and the provider sign a private contract. This is a different problem from an excess charge, and a much bigger one: there is no 15% ceiling, because there is no Medicare claim at all.
So an excess charge is not a penalty, a surprise fee, or anything a hospital billing department invented. It is a specific, capped consequence of one specific billing status.
The 15% is not 15% of what you think
Here is the detail that separates a sourced answer from a repeated one.
CMS spells out the arithmetic on its Physician Fee Schedule documentation page: “The Medicare limiting charge is set by law at 115 percent of the payment amount for the service furnished by the nonparticipating physician. However, the law sets the payment amount for nonparticipating physicians at 95 percent of the payment amount for participating physicians.” CMS then does the multiplication for you — 95% of 115% “is equivalent to multiplying the amount by a factor of 1.0925 (or 109.25 percent)” (CMS.gov).
Read that twice, because it means two things at once:
- A non-participating doctor gets paid less by Medicare than a participating one — 5% less on the fee schedule.
- The most they can bill you is 109.25% of the ordinary fee schedule amount, not 115% of it.
The practical translation: the true excess above what a participating doctor would have charged is about 9.25%, not 15%. The 15% is measured against the reduced non-participating amount. Medicare.gov’s plain-English version — “no more than 15% above the Medicare-approved amount” — is correct, because for a non-participating provider the approved amount is the reduced one.
What an excess charge actually costs on one bill
Numbers make this concrete. The figures below are illustrative — the actual fee schedule amount varies by procedure code and by Medicare payment locality, and Florida has several. What does not vary is the structure.
Assume a specialist visit with a $200 participating fee schedule amount, and assume you have already met the 2026 Part B deductible of $283 (CMS.gov).
| Doctor accepts assignment | Doctor is non-participating | |
|---|---|---|
| Fee schedule amount | $200.00 | $200.00 |
| Medicare-approved amount | $200.00 | $190.00 (95%) |
| Most the doctor may bill you | $200.00 | $218.50 (limiting charge) |
| Medicare pays (80%) | $160.00 | $152.00 |
| Your coinsurance (20%) | $40.00 | $38.00 |
| Part B excess charge | $0.00 | $28.50 |
| Your total | $40.00 | $66.50 |
Your coinsurance actually goes down by two dollars, because 20% of a smaller approved amount is smaller. The excess charge more than erases that. Net difference on this one visit: $26.50.
That is the honest scale of it. One office visit is a rounding error. A year of specialist visits, a surgery, a course of radiation therapy or a run of outpatient physical therapy is not — and those are exactly the categories the limiting charge covers.
Which services can carry an excess charge?
CMS’s Medicare Learning Network lists the services the limiting charge applies to, “regardless of who provides them or bills for them”:
- Physicians’ services
- Diagnostic tests
- Outpatient physical therapy from an independent practicing physical therapist
- Outpatient occupational therapy from an independent practicing occupational therapist
- Radiation therapy, including x-ray, radium and radioactive isotope therapy
- Services and supplies furnished incident to a physician’s service that are commonly furnished in a physician’s office
CMS adds one exclusion in the same breath: the limiting charge does not apply to DMEPOS claims — durable medical equipment, prosthetics, orthotics and supplies (CMS.gov MLN).
Notice what is not on that list. Inpatient hospital care is a Part A benefit, so excess charges are not the mechanism there — the 2026 Part A deductible of $1,736 per benefit period is. Our annual Medicare cost estimator puts the Part A, Part B and supplement pieces into one yearly figure if you want to see them together.
Do Part B excess charges apply in Florida?
Yes. A small number of states have passed what are informally called Medicare Overcharge Measure laws, which prohibit providers from billing excess charges to residents. Florida is not one of them. Chapter 627 of the Florida Statutes regulates Medicare supplement policies — how they are issued, renewed and replaced — not what a non-participating physician may bill a patient (Fla. Stat. 627.6741).
That single fact is what makes this a Florida question rather than a national one, and it cuts in two directions.
It raises the stakes on the plan-letter decision. In a state that bans excess charges, the difference between Plan G and Plan N on this line item is zero, and a Plan N buyer there is giving up nothing. In Florida, they are accepting a real if usually small exposure.
It follows you when you travel. Original Medicare and a Medigap policy work with any provider nationwide who accepts Medicare, which is a large part of why Florida retirees who spend summers north hold them. But that portability runs both ways: a Florida Plan N holder seeing a non-participating specialist in another state is exposed there too, whatever that state’s own law says about its residents.
Florida law does give you something useful in return. Under Fla. Stat. 627.6741, a Medigap insurer must offer you a policy without medical underwriting — no conditioning the issue on, and no pricing by, your health status — in two situations: during the six-month period beginning with the first month you are 65 and enrolled in Part B, and during the two-month period after coverage under a group health insurance policy terminates. Florida extends the same protection to people under 65 who qualify for Medicare by disability or end-stage renal disease, which is a genuine state-level addition; federal law does not require it.
Translated: the moment to secure excess-charge coverage is inside one of those windows. Outside them, an insurer in Florida may underwrite you, and may decline. We wrote about that door closing in what happens if you miss your Medigap open enrollment window, and the enrollment window checker will date yours.
Which Medicare Supplement plans cover Part B excess charges?
Medigap benefits are standardized by letter, so a Plan G is a Plan G regardless of which company sells it. On Medicare.gov’s plan-benefits chart, the “Part B excess charge” row is checked for exactly two letters (Medicare.gov):
| Medigap plan | Covers Part B excess charges? | Availability |
|---|---|---|
| Plan F | Yes | Only if you were first eligible for Medicare before January 1, 2020 |
| Plan G | Yes | Available to anyone eligible for Medicare |
| Plan N | No | Available; also has copays up to $20 for some office visits, up to $50 for some ER visits |
| Plans A, B, C, D, K, L, M | No | Varies |
Two footnotes that matter and are easy to miss. High-deductible versions of Plans F and G exist in some states, and they pay nothing — including excess charges — until you have paid $2,950 in covered costs in 2026. And Plans K and L cap your annual out-of-pocket at $8,000 and $4,000 respectively in 2026, after which they pay 100% of covered services; excess charges are not among the services they cover in the first place (all figures: Medicare.gov).
Plan G or Plan N: what is the excess-charge gap worth?
This is the decision the excess-charge question is really standing in for, and it does not have one right answer.
Plan N generally costs less per month. In exchange you take on three things Plan G covers: the office and ER copays, the Part B excess charges, and the possibility that any of them lands in a year you did not budget for. Plan G costs more per month and hands those back to the insurer.
The arithmetic is a straightforward comparison of a known monthly number against an unknown annual one:
- The premium difference is certain. It is a fixed number, every month, for as long as you hold the policy.
- The excess-charge exposure is not. It depends entirely on which providers you use, and how often. Someone whose primary care physician and two specialists all accept assignment may go a decade without seeing a single excess charge. Someone who gets referred to a non-participating surgeon in a year that also brings imaging and physical therapy will see several.
Neither plan is the correct one in the abstract. What settles it is your own providers and your own tolerance for a variable bill — and it is worth running rather than guessing. The Plan G vs Plan N comparison works the copays and the premium difference through with your numbers.
One more input worth having: the Florida Office of Insurance Regulation publishes a CHOICES rate comparison of Medicare Supplement rates by Florida county and age. It is the state regulator’s own filing data, not a quote form, and it will tell you what the Plan G–Plan N premium gap actually looks like where you live before you decide what that gap is buying.
How do you find out whether your own doctor accepts assignment?
This is the step that turns a general worry into a specific, answerable question, and it takes about ten minutes.
- Use Medicare’s own provider search. Medicare.gov’s care-provider tool reports whether a clinician accepts Medicare assignment. Check each doctor you actually see, not the practice name on the building.
- Ask the billing office directly, before you book. The phrasing that gets a clean answer is: “Do you accept Medicare assignment?” — not “do you take Medicare,” which a non-participating provider can also answer yes to.
- Ask again when you get a referral. Your assignment-accepting internist can refer you to a non-participating specialist without anyone mentioning it. Referrals are where most excess charges originate.
- Check before a scheduled procedure, not after. Surgery, imaging and therapy series are where the dollars are, and they are also the ones you have time to check.
CMS states on its participation page that it continues to have a high participation rate nationally, but it does not publish a Florida-specific figure there (CMS.gov). We have not found a current .gov breakdown by state, so we are not going to quote one. The national share is not the number that decides your bill anyway — the status of the four or five clinicians you actually see is.
What to do if you are billed an excess charge
- Check it against the Medicare Summary Notice. Your MSN shows the Medicare-approved amount and the maximum you may be billed for each service. If the bill exceeds the limiting charge, it is not a legitimate charge.
- Call the billing office with the specific number. Errors here are common and usually clerical. Ask them to show the limiting charge they calculated.
- Send it to your Medigap carrier if you hold Plan F or G. Excess charges are a covered benefit under those letters and should be paid, not absorbed.
- Call 1-800-MEDICARE if the charge exceeds the ceiling. CMS treats limiting-charge violations as a compliance matter, not a billing dispute.
The part that is actually urgent
Excess charges are a manageable risk. The window to buy the coverage that handles them is not.
Under Florida law that window is six months from the month you turn 65 and enroll in Part B, plus two months after group coverage ends. Inside it, a Medigap insurer takes you as you are. Outside it, your health history is part of the application, and Plan G — the only currently available letter that pays excess charges — is the one you may be asked to qualify for.
That is the sequencing point. The right time to decide how much variability you want in your medical bills is while the decision is still fully yours to make, not after a diagnosis has narrowed it.
If you would like to look at your own doctors, your own premium gap and which side of that window you are standing on, book a time with Virginia or start with the Medicare planning overview. It is a conversation, not a quote — and this article is general education, not advice about your particular situation.