Health Maintenance Organization (HMO): An HMO is a type of health plan that provides a network of doctors, other health care professionals, hospitals, laboratories and other related services. You usually have to select from providers within your HMO’s network or the care you receive won’t be covered by your health insurance. The HMO may provide most of the care in stand-alone facilities or in community-based facilities.
Preferred Provider Organization (PPO): A PPO is a type of health plan that also provides a network of doctors. However, the network is larger than an HMO, and you can go to any of the doctors, health care professionals and hospitals within that plan. You usually do not need a referral to go to a specialist. However, the costs can be more if a plan participant goes to a doctor or uses a service by a provider not within the plan. Usually, the premiums for a PPO are more expensive than the premiums for an HMO.