A PPO is a Preferred Provider Organization. As a member of a PPO, you can use the doctors and hospitals within the PPO network or go outside of the network for care. You do not need a referral to see a specialist. If you obtain care from a medical provider outside of the PPO network, you will pay more for the service. For example, a PPO might pay 90 percent of the cost for a visit with an in-network doctor but only 70 percent of the cost for a visit to a non-network doctor. You will typically pay a copayment for each visit/service. These copayments are typically higher than an HMO copayment but not always. You will usually be responsible for paying an annual deductible. If you join a PPO, you should find you have more flexibility than with an HMO, but your total out of pocket costs are likely to be somewhat higher.