What is the main distinction between a PPO There are four models of Health Maintenance Organizations which include: The staff model, The network model, The independent practice association model, and the group model. Group of answer choices True Falseand EPO? Group of answer choices EPOs restrict members to a list of preferred or exclusive providers, and PPOs do not. PPOs restrict members to a list of preferred or exclusive providers, and EPOs do not. PPOs do not allow members to see out of network providers, but EPOs do. EPOs require members to see primary care providers prior to seeing a specialist, while PPOs do not