Whether your health insurance will reimburse you for a medical service, and how much your insurance will reimburse you depends on whether you are seeing an in-network or an out-of-network provider and the type of benefits you have.
All insurance plans have networks. A network describes a group of healthcare providers who have entered into an agreement with the insurance company. These agreements or contracts govern the types of medical services for which the insurance company will pay and the amount it will pay.
Under the terms of the agreement, the healthcare provider must submit a claim for the services within a certain number of days. If the insurance company requires your healthcare provider to get an authorization for a certain service, the healthcare provider must do so. After the insurance company receives the claim, it reviews it and decides how much it will pay under the specific agreement it has with that provider. When it has finished reviewing the claim, it sends something both to you and the provider. This is often called an explanation of payment or "EOP." The EOP shows payments, adjustments, and it also tells the healthcare provider how much to bill you—
Remember though, if an authorization is not required or if the insurance company decides the service is not medically necessary, the in-network provider may be able to bill you for that service. It depends on the agreement. So even if you are seeing an in-network provider, it is always a good idea to ask what will happen if the insurance company does not pay, and what the cost will be to you.
If a health care provider is not contracted with your insurance company, then they are an Out-of-Network provider. With a few legal exceptions, Out-of-Network Providers are not governed by the same rules. Out-of-Network Providers can charge you according to their own fee schedule and they are not required to get authorizations for any services they provide to you nor are they required to file your claims.
But some insurance plans provide Out-of-Network Benefits. These policies permit you to get reimbursed when you go to Out-of-Network providers. These types of policies have separate requirements for the amount of coinsurance you must pay and they have a separate deductible for your out-of-network benefits.
Generally, an out-of-network policy will not require you to get an authorization before you have a particular medical service. But that doesn't protect you from having to pay more than you should for a procedure. While a policy with out-of-network benefits permits you to have reimbursed services from an Out-of-Network provider, the insurance company still can decide how much it will reimburse for that service and you will be responsible for paying whatever remains.