Quick Answer
Medicare assignment means a healthcare provider agrees to accept the Medicare-approved amount as full payment for a covered service. You are only responsible for your deductible and 20% coinsurance of the approved amount - nothing more. Providers who don't accept assignment can charge up to 15% above the Medicare-approved amount (called an "excess charge"). Opt-out providers are not bound by Medicare's fee schedule at all.
Coverage Comparison by Plan Type
| Plan Type | Coverage | Notes |
|---|---|---|
| Participating Provider (Accepts Assignment) | Accepts Medicare-approved amount as full payment | You pay deductible + 20% coinsurance of approved amount only; no excess charges |
| Non-Participating Provider | Enrolled in Medicare but doesn't always accept assignment | Can charge up to 15% above Medicare-approved amount (excess charge) |
| Opt-Out Provider | Has formally opted out of Medicare entirely | Not bound by Medicare fee schedule; Medicare will not pay; you pay full price |
| Medigap Plan G or F | Covers Part B excess charges from non-participating providers | Plan F and G cover the 15% excess charge; Plan N does not |
Understanding Your Coverage Options
What Does "Accepting Medicare Assignment" Mean?
When a provider accepts Medicare assignment, they agree to: (1) accept Medicare's approved amount as the maximum they can charge for a covered service, and (2) receive payment directly from Medicare.
The Medicare-approved amount is set by CMS in the Medicare Physician Fee Schedule. The provider cannot charge you more than this amount for covered services.
What It Covers
- Provider bills Medicare directly and accepts the approved amount as full payment
- You pay: Part B deductible ($257 in 2026) + 20% coinsurance of the approved amount
- Provider cannot bill you for the difference between their usual fee and Medicare's approved amount
- Applies to Part B services: doctor visits, outpatient care, durable medical equipment, lab tests
What It Doesn't Cover
- Does not apply to Part A (hospital) services
- Does not apply to Medicare Advantage - MA plans have their own network and cost-sharing
Example: How Assignment Works
Medicare approves $200 for a specialist visit. A participating provider accepts this as full payment. Medicare pays 80% ($160); you pay 20% ($40) plus any remaining deductible. A non-participating provider could charge up to $230 ($200 × 1.15), meaning you'd owe up to $70.
Participating vs. Non-Participating vs. Opt-Out Providers
There are three categories of Medicare providers, each with different rules about what they can charge you.
What It Covers
- Participating: Signed agreement to always accept assignment; cannot charge excess fees
- Non-participating: Enrolled in Medicare but can choose to accept or refuse assignment per claim; can charge up to 15% above approved amount
- Opt-out: Formally opted out of Medicare; signed private contracts with patients; Medicare pays nothing; you pay full fee
- About 95% of Medicare providers are participating (accept assignment)
What It Doesn't Cover
- Opt-out providers: Medicare will not pay for their services (except emergencies)
- Non-participating providers: Can charge excess fees up to 15% above approved amount
Part B Excess Charges
If a non-participating provider does not accept assignment on a claim, they can charge up to 15% above the Medicare-approved amount. This extra amount is called a "Part B excess charge" or "limiting charge."
Most Medigap plans do not cover excess charges. However, Medigap Plan F and Plan G do cover Part B excess charges, protecting you from this additional cost.
What It Covers
- Non-participating provider can charge up to 115% of Medicare-approved amount
- The 15% excess is your responsibility unless you have Plan F or Plan G
- Medigap Plan G: Covers Part B excess charges (available to all new enrollees)
- Medigap Plan F: Covers Part B excess charges (only for those eligible before Jan 1, 2020)
- Medigap Plan N: Does NOT cover Part B excess charges
What It Doesn't Cover
- Plan N, Plan A, Plan B, Plan K, Plan L, Plan M do not cover excess charges
How to Avoid Excess Charges
The easiest way to avoid Part B excess charges is to always use participating providers (those who accept Medicare assignment). You can verify assignment status at Medicare.gov/care-compare or by calling 1-800-MEDICARE.
How to Find Providers that Accept Medicare Assignment
Before scheduling a visit, it's important to confirm that your provider accepts Medicare assignment. About 95% of Medicare-enrolled providers are participating, but it's always worth verifying.
What It Covers
- Use Medicare.gov/care-compare to search for providers by name, specialty, or location
- Call the provider's office directly and ask: "Do you accept Medicare assignment?"
- Call 1-800-MEDICARE (1-800-633-4227) to verify a specific provider
- Check your Medicare Summary Notice (MSN) after a visit to see how the claim was processed
Medicare Assignment: Cost Comparison by Provider Type
| Provider Type | Medicare Pays | You Pay (After Deductible) | Excess Charge | Medigap Covers Excess? |
|---|---|---|---|---|
| Participating (accepts assignment) | 80% of approved amount | 20% of approved amount | None | N/A |
| Non-participating (no assignment) | 80% of approved amount | 20% + up to 15% excess | Up to 15% above approved | Plan F and G only |
| Opt-out provider | $0 | Full provider fee | No limit | No |
✦ Important Exceptions & Notes
Medicare Advantage and Assignment
Medicare assignment rules apply to Original Medicare (Parts A and B). Medicare Advantage plans have their own network of providers and cost-sharing rules. With MA, you typically pay a copay or coinsurance set by your plan, not the 20% coinsurance of the Medicare-approved amount.
Emergency Care from Non-Participating Providers
In a medical emergency, you may receive care from a non-participating or opt-out provider. In these cases, Medicare may still pay, and excess charge rules may be limited. Always follow up with Medicare after emergency care from a non-participating provider.
Mandatory Assignment for Certain Services
Medicare requires mandatory assignment for certain services regardless of provider participation status, including clinical laboratory services, ambulance services, and services provided to Medicaid beneficiaries.
Lab tests and ambulance services always have mandatory assignment.
Medigap and Excess Charges
If you have Medigap Plan G or Plan F, you are protected from Part B excess charges. These plans pay the 15% excess charge on your behalf, so you only owe your standard 20% coinsurance (Plan G) or nothing at all (Plan F, if eligible).
✦ Recent Updates
2026 Medicare Physician Fee Schedule
PassedCMS updated the Medicare Physician Fee Schedule for 2026, adjusting approved amounts for thousands of services. Participating providers must accept these updated amounts as full payment.
Part B Deductible Increased to $257 in 2026
PassedThe Part B deductible increased to $257 in 2026 (from $240 in 2025). This is the amount you pay before Medicare covers its 80% share for Part B services.
Tips for Avoiding Excess Charges
Most Medicare beneficiaries never encounter excess charges because ~95% of providers accept assignment. But it's worth knowing how to protect yourself.
Medicare Assignment Checklist
- Always ask providers: "Do you accept Medicare assignment?"
- Use Medicare.gov/care-compare to verify provider assignment status
- Consider Medigap Plan G if you want protection from excess charges
- Avoid opt-out providers for non-emergency care
- Review your Medicare Summary Notice (MSN) after each visit
- Report providers who charge more than the limiting charge to 1-800-MEDICARE
✦ Frequently Asked Questions
David Haass
AuthorDavid Haass is a licensed insurance agent and Medicare specialist at MedicareFAQ.com.
Ashlee Zareczny
ReviewerAshlee Zareczny is the Compliance & Editorial Manager at MedicareFAQ.