What is Balance Billing?

Legal Definition
Balance billing, sometimes also called extra billing, is the practice of a healthcare provider billing a patient for the difference between what the patient's health insurance chooses to reimburse and what the provider chooses to charge.

Advocates of balance billing argue that it increases the incomes of high-quality healthcare providers, and serves as a measure of their dissatisfaction with insurance company fees. Critics say that balance billing lets providers raise charges through stealth rather than transparent pricing, creates unnecessary administrative costs and patient confusion, and allows insurers to simply pass along costs to patients, rather than helping them to secure good value. It is thought to erode political consensus in favour of a one-tier system of healthcare, and to inhibit some people from getting the care they need, by making that care more expensive.
-- Wikipedia
Legal Definition
Billing a patient based on the actual charges and insurance reimbursement.