Guide

Non-par math: the 95% allowed and the 115% ceiling

Summary

A non-participating Medicare provider is paid from a reduced fee-schedule amount, and when they do not accept assignment on a claim they may bill the patient only up to a hard ceiling called the limiting charge. The non-par amount is set at 95% of the participating amount, and the limiting charge is 115% of that non-par amount. Above the limiting charge, a charge is not just disallowed — the excess is refundable to the patient.

By Gale Editorial · Updated 2026-07-26. Every figure cited to a dated source. How we write.

The two numbers that define non-par

Non-participating status has two moving parts, and Medicare sets both. First, Medicare pays a non-participating clinician from a lower fee-schedule amount than it pays a participating one. Second, when a non-par clinician does not accept assignment on a claim, they may bill the patient directly — but only up to a hard ceiling called the limiting charge 1Ref 1Centers for Medicare & Medicaid Services (2026).Internet-Only Manuals (IOMs).That Medicare's Claims Processing Manual is the operative CMS instruction setting the non-participating fee-schedule reduction, the limiting charge that caps a non-assigned non-par claim, and the refundability of any overcharge.. Above that ceiling a charge is not merely disallowed; the excess is refundable to the patient. Those two figures, the reduced allowed amount and the limiting charge, are what non-par math comes down to.

All of this sits inside the broader participation, non-par, opt-out decision — the once-a-year choice of how you relate to Medicare. Non-par is the middle posture: you stay in the program and can bill Medicare, but you keep a per-claim choice about assignment, and the limiting charge is the price of that flexibility. It is a ceiling on what you can collect from the patient, not a fee you set.

The math: 95% and 115%

Two fixed percentages drive the arithmetic, and they are set in Medicare's operative claims instructions 1Ref 1Centers for Medicare & Medicaid Services (2026).Internet-Only Manuals (IOMs).That Medicare's Claims Processing Manual is the operative CMS instruction setting the non-participating fee-schedule reduction, the limiting charge that caps a non-assigned non-par claim, and the refundability of any overcharge.. The non-participating fee-schedule amount is 95% of the participating amount — a five-percent reduction that is the price of not signing the participation agreement. The limiting charge is 115% of that non-participating amount, and it is the most a non-par clinician who does not accept assignment may bill the patient. Because the limiting charge is a percentage of the already-reduced non-par amount, it works out only modestly above the participating fee, not far above it.

You do not have to run this yourself. Medicare's Physician Fee Schedule search tool prints, for each code and locality, the participating amount, the lower non-participating amount, and the limiting charge in dollars 2Ref 2Centers for Medicare & Medicaid Services (2026).Physician Fee Schedule Search.That CMS's Physician Fee Schedule search tool lists the participating amount, the lower non-participating amount, and the limiting charge for each code by locality.. Enter your most-billed codes for your own locality and read all three figures directly, rather than trusting a percentage you would have to compute against the right base.

Assigned versus non-assigned: who gets paid

Non-par is a per-claim decision, and whether you accept assignment changes who Medicare pays. When a non-par clinician accepts assignment on a claim, Medicare pays them directly from the non-participating amount, and the patient owes only their coinsurance and any unmet deductible — the same flow as a participating claim, just off the lower amount. When the clinician does not accept assignment, they collect from the patient up to the limiting charge, and Medicare sends its reimbursement to the patient rather than to the clinician 1Ref 1Centers for Medicare & Medicaid Services (2026).Internet-Only Manuals (IOMs).That Medicare's Claims Processing Manual is the operative CMS instruction setting the non-participating fee-schedule reduction, the limiting charge that caps a non-assigned non-par claim, and the refundability of any overcharge..

That second path is the whole point of non-par, and its whole risk. You can collect more per visit than the participating amount, but you are now collecting from the patient and waiting while their own Medicare reimbursement arrives separately. It suits a practice whose Medicare patients reliably pay at the time of service, and it burdens one whose patients cannot — which is why the choice belongs in your caseload math, not just your billing setup.

The limiting charge is a ceiling, not a target

The limiting charge caps what you may collect from the patient on a non-assigned claim; it is a legal maximum, not a suggested price 1Ref 1Centers for Medicare & Medicaid Services (2026).Internet-Only Manuals (IOMs).That Medicare's Claims Processing Manual is the operative CMS instruction setting the non-participating fee-schedule reduction, the limiting charge that caps a non-assigned non-par claim, and the refundability of any overcharge.. Billing a patient above it is not permitted, and the overcharge is refundable to the patient whether or not anyone asks — a persistent pattern of overcharges is exactly the kind of thing that draws a contractor's attention and can invite payer audits 3Ref 3Noridian Healthcare Solutions (2026).Noridian Healthcare Solutions — Medicare.That a Medicare Administrative Contractor publishes the limiting-charge guidance, mandatory-assignment services, and overcharge-monitoring rules that bind its jurisdiction — cited as a named contractor example.. Your MAC publishes the limiting-charge rules and the monitoring expectations for its jurisdiction, and CMS publishes which MAC is yours 4Ref 4Centers for Medicare & Medicaid Services (2026).Medicare Administrative Contractors.That Medicare claims are administered regionally and CMS publishes which MAC serves a provider's jurisdiction — the basis for finding your MAC's limiting-charge article..

A few services sit outside the ordinary limiting-charge rule — some are subject to mandatory assignment regardless of your status — so when a code behaves unexpectedly, check your MAC's article for that service rather than assuming the general rule applies 3Ref 3Noridian Healthcare Solutions (2026).Noridian Healthcare Solutions — Medicare.That a Medicare Administrative Contractor publishes the limiting-charge guidance, mandatory-assignment services, and overcharge-monitoring rules that bind its jurisdiction — cited as a named contractor example.. The safe posture is to treat the limiting charge as the line you never cross, not the number you aim for.

When Medicare is not the only payer

The limiting charge assumes an ordinary Medicare-primary claim, and two situations change it. When the patient has secondary coverage, coordination-of-benefits rules decide the payer order, and a Medigap or other secondary plan may pick up the patient's share after Medicare pays — often through automatic crossovers rather than a separate bill 5Ref 5Centers for Medicare & Medicaid Services (2026).Coordination of Benefits and Recovery Overview.That coordination of benefits sets the payer order and routes a dual-eligible patient's Medicare cost-sharing to the state program rather than to the patient, so the limiting charge cannot be billed to a Qualified Medicare Beneficiary.. And when the patient is dual-eligible for Medicare and Medicaid, their Medicare cost-sharing is coordinated to the state program rather than billed to them, so the limiting charge cannot be turned into a bill to a Qualified Medicare Beneficiary 5Ref 5Centers for Medicare & Medicaid Services (2026).Coordination of Benefits and Recovery Overview.That coordination of benefits sets the payer order and routes a dual-eligible patient's Medicare cost-sharing to the state program rather than to the patient, so the limiting charge cannot be billed to a Qualified Medicare Beneficiary.. Charging a dual-eligible patient the limiting charge is a compliance problem, not a collection strategy.

This is why non-par is not a single decision but a per-patient one: the same status produces very different collections depending on who else is paying. Confirm the patient's other coverage before you decide whether to accept assignment, not after.

How to find your three numbers

Every figure here is one you look up for your own codes and locality rather than take on faith 2Ref 2Centers for Medicare & Medicaid Services (2026).Physician Fee Schedule Search.That CMS's Physician Fee Schedule search tool lists the participating amount, the lower non-participating amount, and the limiting charge for each code by locality.. The method is short:

Pull the three amounts. In the Physician Fee Schedule search tool, enter each of your top codes and your locality, and read the participating amount, the non-participating amount, and the limiting charge together 2Ref 2Centers for Medicare & Medicaid Services (2026).Physician Fee Schedule Search.That CMS's Physician Fee Schedule search tool lists the participating amount, the lower non-participating amount, and the limiting charge for each code by locality..
Read your MAC's article. Your MAC publishes the limiting-charge guidance, any mandatory-assignment services, and its monitoring rules for your jurisdiction 3Ref 3Noridian Healthcare Solutions (2026).Noridian Healthcare Solutions — Medicare.That a Medicare Administrative Contractor publishes the limiting-charge guidance, mandatory-assignment services, and overcharge-monitoring rules that bind its jurisdiction — cited as a named contractor example., and CMS's directory tells you which MAC that is 4Ref 4Centers for Medicare & Medicaid Services (2026).Medicare Administrative Contractors.That Medicare claims are administered regionally and CMS publishes which MAC serves a provider's jurisdiction — the basis for finding your MAC's limiting-charge article..
Decide per claim, not once. Because assignment is a per-claim choice and the patient's other coverage changes the outcome, non-par rewards knowing the numbers before the visit, not after the remittance.

Run your top ten codes through the tool once, note the limiting charge next to each, and the recurring question of what you may collect answers itself.

Common questions

On a non-assigned claim, up to the limiting charge — 115% of the non-participating amount, which itself is 95% of the participating fee. In practice that works out only modestly above the participating amount, not far above it. Look up the exact limiting charge for each of your codes in the fee-schedule tool, since the dollar figure varies by code and locality.

The patient. When a non-participating provider does not accept assignment, they collect from the patient up to the limiting charge, and Medicare sends its reimbursement to the patient separately. You carry the collection and the timing risk. On a claim where you do accept assignment, Medicare pays you directly from the lower non-participating amount instead.

No. The limiting charge is a legal maximum, not a negotiable price, and the excess is refundable to the patient regardless of any agreement. A pattern of overcharging is something your MAC monitors and can act on. Billing patients at your own rate with no Medicare cap requires opting out entirely, which is a separate and more involved posture.

No. For a patient dual-eligible for Medicare and Medicaid, the Medicare cost-sharing is coordinated to the state program rather than billed to the patient, so the limiting charge cannot be turned into a bill to a Qualified Medicare Beneficiary. Charging one is a compliance problem. Confirm dual status before you collect anything at the visit.

In CMS's Physician Fee Schedule search tool. For each code and your locality it lists the participating amount, the non-participating amount, and the limiting charge side by side. Pull your most-billed codes once and record the limiting charge next to each, so you know your ceiling before the visit rather than after.

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References

1.Centers for Medicare & Medicaid Services (2026). Internet-Only Manuals (IOMs). Centers for Medicare & Medicaid Services (CMS). link ✓That Medicare's Claims Processing Manual is the operative CMS instruction setting the non-participating fee-schedule reduction, the limiting charge that caps a non-assigned non-par claim, and the refundability of any overcharge.
2.Centers for Medicare & Medicaid Services (2026). Physician Fee Schedule Search. Centers for Medicare & Medicaid Services (CMS). link ✓That CMS's Physician Fee Schedule search tool lists the participating amount, the lower non-participating amount, and the limiting charge for each code by locality.
3.Noridian Healthcare Solutions (2026). Noridian Healthcare Solutions — Medicare. Medicare Administrative Contractor portal. link ✓That a Medicare Administrative Contractor publishes the limiting-charge guidance, mandatory-assignment services, and overcharge-monitoring rules that bind its jurisdiction — cited as a named contractor example.
4.Centers for Medicare & Medicaid Services (2026). Medicare Administrative Contractors. Centers for Medicare & Medicaid Services (CMS). link ✓That Medicare claims are administered regionally and CMS publishes which MAC serves a provider's jurisdiction — the basis for finding your MAC's limiting-charge article.
5.Centers for Medicare & Medicaid Services (2026). Coordination of Benefits and Recovery Overview. Centers for Medicare & Medicaid Services (CMS). link ✓That coordination of benefits sets the payer order and routes a dual-eligible patient's Medicare cost-sharing to the state program rather than to the patient, so the limiting charge cannot be billed to a Qualified Medicare Beneficiary.

https://www.gale.care/for-providers/mc-limiting-charge-nonpar · 5 sources. Competitor details are cited to dated public sources and maintained as they change; figures are estimates, not commitments. Synthetic demonstration.

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