Imagine two people, with the same health insurance companies, walk into an emergency room. The patients have identical symptoms and receive the same diagnoses and subsequent procedures and treatments. Both patients should get an identical bill, right? But in reality, one patient could receive a bill where nearly everything is covered by insurance, and the other could receive a bill where little or nothing is covered. For some patients, this can be the difference between an emergency room bill that cost several hundred dollars, versus one costing tens of thousands.