Choosing between participating and non-participating status affects Medicare reimbursement, patient collections, claim workflows, and the amount a practice may charge. The terms sound similar, but they create different obligations. This guide explains PAR vs Non-PAR providers in Original Medicare, including assignment rules, the limiting charge, and the steps practices should review before changing status.
Important: Medicare participation is not the same as a commercial payer network contract. It is also different from opting out of Medicare. Practices should evaluate each arrangement separately and confirm current requirements with their Medicare Administrative Contractor.
PAR vs Non-PAR Providers at a Glance
| Issue | Participating provider | Non-participating provider |
|---|---|---|
| Assignment | Accepts assignment on all Medicare-covered services | May accept assignment claim by claim |
| Medicare allowed amount | Receives the full applicable Physician Fee Schedule allowed amount | Allowed amount is generally 95% of the PAR amount |
| Payment on assigned claims | Medicare pays the provider directly | Medicare pays the provider directly |
| Unassigned claims | Not permitted as a routine participation choice | Provider may collect from the patient, subject to Medicare rules |
| Maximum charge | Medicare allowed amount, plus applicable patient responsibility | Limiting charge applies to most unassigned physician services |
| Administrative impact | More consistent payment and collection workflow | More claim-level decisions and patient collection responsibility |
What Medicare Participation and Assignment Actually Mean
Participation status
A participating, or PAR, physician or supplier signs an agreement to accept assignment for all Medicare-covered services furnished to Medicare patients. The practice accepts the Medicare-approved amount as payment in full and may collect only the applicable deductible, coinsurance, or copayment from the patient.
A non-participating, or Non-PAR, provider remains enrolled in Medicare but has not signed a participation agreement. Non-PAR providers can choose whether to accept assignment for many individual claims. That flexibility comes with a lower Medicare fee schedule amount and added collection responsibilities.
Accepting assignment
Assignment is a payment agreement for a claim. When a provider accepts assignment, the provider agrees to the Medicare-approved amount and Medicare pays its share directly to the provider. The patient remains responsible for the deductible and coinsurance.
Participation is the provider’s overall annual status. Assignment is the payment choice applied to a claim. A PAR provider accepts assignment consistently, while a Non-PAR provider may make that decision claim by claim when permitted.
Network status
In-network and out-of-network usually describe a provider’s relationship with a commercial health plan or Medicare Advantage plan. PAR and Non-PAR describe participation in Original Medicare. A provider can be Non-PAR with Original Medicare and still have separate network contracts with other payers. Accurate enrollment and contract records are essential, which is why many practices use professional medical credentialing services when adding providers or changing payer relationships.
What Is a Participating Provider?
A participating provider agrees to accept assignment on every Medicare-covered service. The provider bills Medicare, receives Medicare’s payment directly, and bills the patient only for valid cost-sharing amounts. This creates a predictable workflow for staff and patients.
How PAR reimbursement works
For an assigned Part B claim, Medicare generally pays 80% of the Medicare-approved amount after the deductible is met. The patient or secondary payer is responsible for the remaining 20%. Exact payment depends on coverage, locality, modifiers, sequestration, and other claim-specific factors.
Benefits and limitations
PAR status can reduce front-desk confusion, simplify payment posting, and make patient estimates easier. Medicare also sends claim information to Medigap insurers for participating providers. The tradeoff is that the practice cannot charge more than the Medicare-approved amount for covered services and must accept assignment on all eligible claims.
What Is a Non-Participating Provider?
A Non-PAR provider is enrolled in Medicare but does not have a participation agreement. Medicare generally calculates the Non-PAR allowed amount at 95% of the amount paid under the participating fee schedule. The provider may accept assignment or submit an unassigned claim, subject to applicable rules.
Assigned claims
If a Non-PAR provider accepts assignment, Medicare pays the provider directly based on the lower Non-PAR allowed amount. The provider cannot balance bill above that amount and may collect only the patient’s valid cost sharing.
Unassigned claims
On an unassigned claim, the provider may require the patient to pay and Medicare generally reimburses the patient. The provider must still submit the claim to Medicare. This approach can increase front-end collections, patient questions, refunds, and reconciliation work. A reliable insurance eligibility verification process helps staff explain expected responsibility before the visit.
The Medicare limiting charge
The limiting charge caps what a Non-PAR provider may bill for most unassigned physician services. It is generally 115% of the Non-PAR fee schedule amount. Because the Non-PAR amount is typically 95% of the PAR amount, the maximum is effectively 109.25% of the PAR amount, not 115% above the PAR amount.
Some services and provider types follow different rules, so staff should verify the applicable fee schedule and limiting charge before collecting payment. The CMS Medicare participation guidance provides the current federal framework.
PAR vs Non-PAR Payment Example
Assume the PAR Medicare-approved amount for a covered service is $100 and the patient’s deductible has been met.
- PAR assigned claim: Medicare generally pays $80 and the patient or secondary payer owes $20.
- Non-PAR assigned claim: The allowed amount is generally $95. Medicare generally pays $76 and the patient or secondary payer owes $19.
- Non-PAR unassigned claim: The limiting charge may be up to $109.25. The provider collects from the patient, and Medicare generally reimburses the patient based on 80% of the $95 Non-PAR allowed amount.
This simplified example excludes deductibles, sequestration, secondary coverage, locality adjustments, and services for which assignment is mandatory.
How Participation Status Affects Patients
Patients usually have a simpler experience with PAR providers because charges follow the Medicare-approved amount and Medicare pays the provider directly. With a Non-PAR provider, the patient may face a higher charge and may need to pay before receiving Medicare reimbursement.
Clear financial policies matter. Staff should explain assignment, estimated cost sharing, secondary insurance, and refund timing before service. Medicare beneficiaries can also check whether a provider accepts assignment through Medicare’s provider payment guidance.
Non-PAR vs Opting Out of Medicare
Non-PAR status does not mean a provider has opted out. A Non-PAR provider is still enrolled, submits Medicare claims, and follows Medicare payment limits. An opted-out physician or practitioner enters private contracts with Medicare patients and generally cannot submit Medicare claims for covered services except for qualifying emergency or urgent care circumstances.
Opt-out affidavits generally remain effective for two years and renew automatically unless properly terminated. Because opting out changes both contracting and billing obligations, practices should obtain qualified legal and compliance advice before making that decision.
Which Status Fits Your Medical Practice?
Choose PAR when:
- Your practice values predictable reimbursement and simpler patient billing.
- A large share of your patients has Original Medicare.
- You want Medicare to pay the practice directly on every covered claim.
- Your team wants to minimize claim-level assignment decisions.
Consider Non-PAR when:
- Your practice can manage patient collections and detailed financial communication.
- You have analyzed the actual reimbursement difference by service mix.
- You understand which services require assignment.
- Your patients can accommodate the potential upfront payment requirements.
The best choice is not based on the limiting charge alone. Compare expected collections, bad debt, staff time, patient retention, secondary-payer behavior, and payer mix. A broader revenue cycle management review can show whether theoretical gains will translate into collected revenue.
Operational and Billing Risks to Review
Non-PAR billing requires accurate fee tables, claim-level assignment controls, written patient policies, and close payment reconciliation. Common problems include charging above the limiting amount, treating Non-PAR as opted out, failing to submit an unassigned claim, and confusing Original Medicare rules with Medicare Advantage contracts.
PAR practices have risks too. Incorrect cost-sharing calculations, outdated enrollment information, or billing patients beyond the approved amount can create refunds and compliance exposure. Documented workflows and regular account review help both models. Practices without enough internal capacity may benefit from specialized physician billing services.
How to Change Medicare Participation Status
CMS-460
A provider choosing participating status completes the Medicare Participating Physician or Supplier Agreement, Form CMS-460, and submits it to the appropriate Medicare Administrative Contractor. New providers may submit the agreement with their enrollment application.
Annual participation period
CMS states that physicians and suppliers may make their participation decision each year from mid-November through December 31 for the following year. A participating provider that wants to become Non-PAR must notify each applicable MAC in writing before the deadline. Existing PAR providers who wish to remain PAR generally do not need to act.
Contract checks
Before changing status, verify Medicare enrollment data, reassignment arrangements, group affiliations, Medicare Advantage contracts, commercial payer agreements, and patient notices. Confirm the effective date in writing and update billing systems only after the MAC recognizes the change.
PAR vs Non-PAR Decision Checklist
- Calculate the revenue effect using your actual Medicare service mix.
- Estimate patient collection costs and potential bad debt.
- Confirm which services require assignment.
- Review Medicare Advantage and commercial contracts separately.
- Train scheduling, front-desk, billing, and refund teams.
- Validate fee schedules and limiting-charge logic in the billing system.
- Check the CMS deadline and obtain confirmation from every relevant MAC.
Frequently Asked Questions
What is the difference between PAR and Non-PAR providers?
A PAR provider accepts assignment for all Medicare-covered services. A Non-PAR provider is enrolled in Medicare but may accept assignment on a claim-by-claim basis and generally uses a Medicare allowed amount equal to 95% of the PAR amount.
Can a Non-PAR provider accept assignment?
Yes. A Non-PAR provider may accept assignment on individual claims when Medicare rules allow it. For an assigned claim, the provider accepts the Non-PAR approved amount as payment in full.
How much more can a Non-PAR provider charge?
For most unassigned physician services, the limiting charge is 115% of the Non-PAR approved amount. This commonly equals 109.25% of the PAR approved amount.
Does Medicare pay an opted-out provider?
Generally, no. An opted-out practitioner uses a private contract with the Medicare patient, and neither party submits a Medicare claim for covered services except in limited emergency or urgent care situations.
Can a provider change Medicare participation status?
Yes. CMS provides an annual participation period from mid-November through December 31. The required action depends on the provider’s current status and intended status for the next year.
Is Non-PAR the same as out-of-network?
No. Non-PAR is an Original Medicare participation status. Out-of-network describes a provider’s relationship with a particular health plan. The same provider can have different arrangements with Medicare Advantage and commercial payers.
How Swift Medical Billing Can Help
A participation decision should be supported by real reimbursement and collection data. Swift Medical Billing can review enrollment records, fee schedules, patient balances, claim workflows, and payer contracts before your practice changes status. We also help teams maintain accurate billing procedures after the decision takes effect.
Contact Swift Medical Billing to evaluate the operational and financial impact of PAR vs Non-PAR status for your practice.
