PPOs are comprehensive networks of healthcare providers that are set up by employers, by insurers, and by major providers, such as hospitals and groups of doctors. The PPO sponsor negotiates for reduced fees for services contracted through the PPO. Under a PPO plan, the patient also has the choice of seeing nonparticipating doctors, but those doctors' services may not be fully covered.
HMOs offer comprehensive health care for a prepaid fee instead of reimbursing the provider on a fee-for-service basis, thereby shifting the risk of unexpected costs to the provider.Staff model HMOs provide services at one or more locations solely to members through professionals who are full- or part-time employees of the HMO. Individual practice associations (IPA) deliver services through a group of professionals who incorporate to care for HMO members. IPAs offer a wider choice of available physicians and, sometimes, more convenient locations. Group model HMOs deliver services through physicians' groups and local hospitals that the HMO contracts with to provide health services to members at designated health centers.
A POS or Point of Service plan is kind of like an HMO and PPO combined type health care plan. You have more flexibility than a regular HMO, but pay a smaller fee and deducible than a PPO.