Short answer: EPOs generally don’t cover out-of-network care except for emergencies, so non-emergency services outside the network are the member’s full responsibility.
An EPO covers in-network care only. Outside of true emergencies, non-network services typically aren’t covered at all, so the member pays the entire bill. That’s the trade-off for an EPO’s lower premium relative to a PPO. If out-of-network access matters to you, a PPO or POS plan is the better fit.