When it comes to health insurance coverage, insurance companies have lists of physicians, clinics, hospitals, or other health care providers that have contracts with them. These lists, or provider networks, also include specific services that the insurance companies are willing to pay for— like rehab.
So, any coverage that pays for services in a provider network is "in-network coverage."
Now, if your insurance company doesn't cover something, it's usually because the service or provider is not part of the provider network. However, your insurance company might still help pay for outside services through "out-of-network coverage."
For example, suppose you go to a doctor’s office that does not accept your insurance plan. This means that either that particular office or the service you need is not in your insurance’s provider network. Even so, your policy may allow you to use insurance to cover part of the cost of the visit.