Short answer: POS plans do cover out-of-network care, but at higher cost-sharing, and you usually need a referral from your primary care doctor to get the best coverage.
A Point-of-Service (POS) plan is a hybrid: in network it works like an HMO (choose a PCP, use referrals for the lowest cost), but it also includes out-of-network benefits like a PPO at higher deductibles and coinsurance. Out-of-network care without the required referral may be reduced or denied, so the referral step matters. POS plans suit members who want mostly managed in-network care with occasional out-of-network flexibility.