The Medicare-approved amount is what Original Medicare sets as payment for a covered service or item. It may be lower than the provider’s usual charge. For many Part B services, you generally pay 20% of the approved amount after meeting the deductible when the provider accepts assignment.

How Assignment Changes Billing

A provider that accepts assignment agrees to accept the Medicare-approved amount as full payment for a covered service. The provider may bill you only for applicable deductible and coinsurance and must submit the Medicare claim.

A non-participating provider may accept assignment case by case. If the provider does not accept it, you may need to pay upfront and may owe more than the approved amount. In many cases, federal rules limit the extra amount the provider can charge.

What the Approved Amount Does Not Mean

It is not a promise that Medicare will cover every service. Medicare must cover the service or item. Care to diagnose or treat a health problem must be medically necessary. Preventive care, such as a screening, must meet Medicare’s rules for that benefit. The provider must also keep the required records and follow Medicare’s rules.

The familiar 20% calculation also does not apply identically in every setting. Hospital outpatient departments, durable medical equipment, preventive services, and other benefits can have different payment rules.

Medicare Advantage plans use plan-specific copayments and coinsurance rather than simply applying Original Medicare's approved amount to every bill.

How to Check Your Share

Ask whether the provider accepts assignment. After Medicare processes a claim, review your Medicare Summary Notice, which shows what was billed, what Medicare approved and paid, and the maximum amount you may owe.

For example, suppose a provider charges $150 but Medicare approves $100 for a Part B service. If the provider accepts assignment and you have met your deductible, Medicare pays $80 and you owe $20. You do not owe the $50 difference between the provider’s charge and the approved amount. These are made-up figures, not a cost estimate.

The Medicare Summary Notice is not a bill. Match its service date, provider and patient amount to the provider’s invoice. If the invoice asks for more, contact the billing office before paying; supplemental insurance may also owe part of the patient amount.

Medicare policy sources last checked: October 8, 2026.