In a controversial practice known as "balance billing," health-care providers are going after patients for money they don't owe 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...