HMO plans are managed health plans.  Clients will need to choose a primary care provider under a health network.  The primary care provider will manage the care of the client.  Referals will be made to specialist by the primary care provider.  In OC, Kaiser Permanente is a good example of a robust HMO care provider.   Other good choices will be  BlueShield Trio HMO and Anthem HMO plan.