A Preferred Provider Organization (PPO) allows you the freedom to choose your own doctors and facilities. In-network providers give you a larger network discount. You still have benefits for out of network providers. A PPO also allows you to go straight to a specialist without having to ask for a referral from a Primary Care Physician. A Health Maintenance Organization (HMO) may only give access to a limited number of doctors and facilities in its small regional network. If you seek care out-of-network, then the insurance company may not be responsible for any of the bill unless it’s deemed a life-threatening emergency. An HMO typically requires you to have a referral from your Primary Care Physician before being able to see a specialist.