An in-network provider is one contracted with the health insurance company to provide services to plan members for specific pre-negotiated rates. An out-of-network provider is one not contracted with the health insurance plan. Typically, if you visit a physician or other provider within the network, the amount you will be responsible for paying will be less than if you go to an out-of-network provider. Though there are some exceptions, in many cases, the insurance company will either pay less or not pay anything for services you receive from out-of-network providers.
 
As a general rule, PPO, POS, and HMO plans make use of provider networks. Indemnity plans typically do not.