"Medicare assignment" means a doctor or supplier agrees to accept the Medicare-approved amount as full payment for a service. When a provider "accepts assignment," you pay only your deductible and coinsurance — never more. About 96% of doctors accept assignment, but the 4% who don't can charge you 15% above the Medicare-approved amount, called "excess charges."
Three types of provider participation in Medicare:
1. Participating providers ("accept assignment"):
- Sign agreement to accept Medicare-approved amount as full payment
- File claims directly with Medicare
- Cannot bill you for amounts beyond your deductible and coinsurance
- Receive Medicare reimbursement directly
- About 96% of doctors are in this category
Example: Service has Medicare-approved amount of $200. Doctor accepts assignment. After your $283 Part B deductible (2026), Medicare pays 80% ($160). You owe 20% ($40). Total to you: $40. (Or $0 if you have Medigap covering the 20%.)
2. Non-participating providers (don't accept assignment but still treat Medicare patients):
- Don't agree to accept Medicare's allowed amount as full payment
- Can charge up to 115% of the Medicare-approved amount (the "limiting charge")
- The extra 15% is called the Part B excess charge
- May or may not file claims with Medicare; you may need to submit yourself
- About 3–4% of doctors are in this category
Example: Same service, Medicare-approved amount $200. Non-participating doctor charges 115% = $230. After $283 deductible, Medicare pays 80% of $200 = $160. You owe the remaining $70 ($230 - $160). Without Medigap, you pay an extra $30 vs. an assignment-accepting doctor.
3. Opt-out providers (don't accept Medicare at all):
- Have formally opted out of Medicare for 2 years
- Cannot bill Medicare or Medigap for any covered services
- You sign a private contract agreeing to pay full retail price
- Common in concierge medicine, specialized practices, some psychiatrists
- Less than 1% of doctors
Example: Opt-out specialist charges $500 for a visit. Medicare pays $0. You pay $500 entirely out of pocket. No reimbursement.
Why this matters most for Original Medicare beneficiaries:
If you're on Medicare Advantage, assignment doesn't apply the same way — your MA plan negotiates rates with in-network providers, and you face the in-network cost-sharing structure.
If you're on Original Medicare, the provider's assignment status directly affects what you pay.
The Medigap Plan G and Plan F protection:
Medigap Plan G and Plan F (and Plan F-High Deductible) cover Part B excess charges. So if you're on Plan G and see a non-participating doctor:
- Medicare pays 80% of approved amount
- Plan G pays 20% coinsurance + the excess charge
- Your out-of-pocket: $283 Part B deductible (Plan G doesn't cover this)
Medigap Plans A, B, K, L, M, N do NOT cover Part B excess charges. Plan N specifically may leave you exposed to excess charges.
State variation:
8 states ban Part B excess charges entirely:
- Connecticut
- Massachusetts
- Minnesota
- New York
- Ohio
- Pennsylvania
- Rhode Island
- Vermont
In these states, all doctors who accept Medicare must accept assignment. Excess charges aren't a concern.
In the other 42 states, the 4% of doctors who don't accept assignment can charge the 15% excess.
Other countries / abroad:
Medicare doesn't cover most care outside the U.S. Specific exceptions exist for Canada and Mexico in narrow circumstances. Medigap Plan G and others include 80% foreign travel emergency coverage up to $50,000 lifetime maximum.
How to find providers who accept assignment:
- Medicare.gov "Care Compare" — search for doctors and hospitals; their assignment status is shown
- Ask the office directly: "Do you accept Medicare assignment?" before scheduling
- Call 1-800-MEDICARE for local provider lookups
- Use Medicare Advantage: networks within an MA plan have negotiated rates regardless of "assignment" status
The quality-cost trade:
Providers who don't accept assignment often:
- Operate in higher-end concierge or specialty practices
- Have shorter wait times, longer appointments
- Provide more personalized service
- Some patients value this enough to pay the 15% premium
Providers who opt out entirely (1%):
- Often boutique concierge medicine, $1,500–$5,000 annual membership fees in addition to per-visit charges
- May be the only option for certain specialists in rural areas
- Offer cash-pay rates that can be lower than insurance retail
For Medicare Advantage members:
Assignment doesn't apply directly. Instead:
- In-network: plan-negotiated rate, you pay copay or coinsurance
- Out-of-network on PPO: plan covers at higher cost-sharing
- Out-of-network on HMO: not covered
The under-told story — DME (Durable Medical Equipment) suppliers:
The assignment concept also applies to DME (wheelchairs, oxygen, CPAP, blood-glucose meters, etc.). Some DME suppliers accept assignment; some don't. Non-assignment suppliers can charge significantly more for the same equipment.
Medicare's Competitive Bidding Program covers DME in many areas. Look for "Medicare-enrolled" suppliers via Medicare.gov to ensure assignment.
What to do next: Call (866) 534-1886. If you're considering Original Medicare + Medigap, we recommend Plan G (which covers excess charges) and verify your specific doctors accept assignment. If you're considering MA, we map your doctors to plan networks. Free.