1.Health Maintenance Organization (HMO): This is a common type of health insurance plan and is usually less expensive than PPO or PPOS. They were created in an attempt to defray the rising cost of 0insurance and health care. In essence, the network of doctors and health service providers agree to offer their services at a reduced cost that is offset by the increase number of patients that will utilize these doctors through their health plan.

HMO's require the patient to use doctors, hospitals, specialists that are in the HMO's network. Care is coordinated through a primary care physician that will decide whether or not the services of a specialist are required. If the primary care physician deems that in fact the services of the specialist are required, he/she will write a referral so that the specialist visit will be insured. Without a referral, the services performed by the specialist may not be covered.

2.Preferred Provider Organization (PPO): Unlike an HMO, PPO's allow its participants to see any doctor they wish. Although there is a network of doctors in the preferred plan as with an HMO, participants are not required to use them. The higher cost, however, of the out of network doctors encourages participants to use the in network doctors. Referrals are usually required to visit out of network doctors.

3.Point of Service Plans (PPOS) is a type of mix between HMO and PPO. New participants must select a primary care physician who, just like in an HMO, will manage the patient's health care. However, participants may choose to select in or out of network care providers. If out of network services are selected without a referral from a primary care physician, the visit will be treated as an out of network visit and will be covered. This differs from an HMO, which would not cover a non-referred doctor visit.