Balance Billing

I read an interesting article from Business Week, Medical Bills You Shouldn't Pay, referring to 'balance billing'

As health-care costs continue to soar, millions of confused consumers are paying medical bills they don't actually owe. Typically this occurs when an insurance plan covers less than what a doctor, hospital, or lab service wants to be paid. The health-care provider demands the balance from the patient. Uncertain and fearing the calls of a debt collector, the patient pays up.

Most consumers don't realize it, but this common practice, known as balance billing, often is illegal. When doctors or hospitals think an insurer has reimbursed too little, state and federal laws generally bar the medical providers from pressuring patients to pay the difference. Instead, doctors and hospitals should be wrangling directly with insurers. Economists and patient advocates estimate that consumers pay $1 billion or more a year for which they're not responsible.

What's important to understand is that often times your employer will have a 90/10 or 80/20 plan where they have a fixed, negotiated fee schedule, and they will pay 80% or 90% of it, and you are required to pay the remaining. So if the doctor sends a bill of $100 to your insurance who then negotiates it to a rate of $50 and then pays $45, (90%) your doctor is allowed to bill you the remaining $5, but not the negotiated down price of $50.