Short answer: No. PPO members can see any in-network provider, including specialists, without choosing a PCP or getting a referral, and they also have out-of-network benefits at a higher cost.
A Preferred Provider Organization (PPO) is the most flexible common plan type. There’s no requirement to designate a primary care physician, and you can book a specialist directly without a referral. PPOs also cover out-of-network care, though at higher cost-sharing and with possible balance billing. That flexibility is why PPOs typically carry higher premiums than HMO or EPO plans.