Balance billing is a provider practice of billing for expenses either not covered or partially covered by your health plan. For example, if some of the services provided during your doctor’s visit aren’t covered by your plan, the doctor will bill you directly for those services. Balance billing may also occur when the provider’s fees are higher than the health insurance company considers usual and customary for a particular service. In this case, you may be responsible for paying the balance, unless the agreement between your plan and the provider prohibits balance billing.