Health insurance costs can be confusing, and Medicare’s billing system is no exception. Below is a step-by-step guide that illustrates how Medicare billing works from before a patient gets sick or injured until the time they receive a bill in the mail.

1. Medicare sets a value for everything it covers.
Every product and service covered by Medicare is given a value based on what Medicare decides it’s worth. This standard is used across the board and is known as the “Medicare-approved amount.”
For example, if Medicare determines that a particular type of X-ray is worth $100, then Medicare will pay health care providers $100 for that service regardless of what the provider would normally charge a non-Medicare patient.
2. A health care provider must declare whether or not they accept Medicare assignment.
“Accepting assignment” means that a doctor or health care provider has agreed to accept the Medicare-approved amount as full payment for their services. The overwhelming majority of health care providers in the United States accept Medicare assignment.
If a provider chooses not to accept assignment, they may still treat Medicare patients but will be allowed to charge up to 15 percent more for their product or service. These are known as “excess charges.”