A POS health plan stands for "point of service" and is a mix between an HMO and a PPO-style health insurance policy. With a POS health plan, you have more choices than with an HMO. You may need to select a primary care provider and need a referral to see a specialist. But with a POS plan you have the choice to use doctors, hospitals, and other providers that are not in your health plan's network. However, you will have to pay more for using out-of-network providers.