Short answer: An EPO offers PPO-like freedom inside the network, usually no PCP or referrals, but covers in-network care only, with no out-of-network benefits except emergencies.
An Exclusive Provider Organization (EPO) sits between an HMO and a PPO. Like a PPO, it usually doesn’t require a primary care physician or referrals, so you can go straight to in-network specialists. Like an HMO, it covers in-network care only; out-of-network services (except emergencies) are the member’s full responsibility. The trade-off is a premium that’s typically lower than a comparable PPO.