In the United States, there is no federal law mandating that hospitals or healthcare providers must bill private insurance, Medicaid, or Medicare. They can choose whether to accept insurance and make agreements with specific plans. While many providers do bill insurance, including Medicare and Medicaid, some opt out of certain networks. This choice affects both provider and patient, as non-participating providers may charge more, leaving patients with a bigger bill to pay.

Normally, hospitals start billing by sending claims to the patient’s main health insurance. When there’s third-party liability, they use a process called Coordination of Benefits. Here, they figure out the order in which different insurance policies will help cover the patient’s medical costs. Good communication between the hospital and the patient about financial responsibilities is key during this time.