What is the general distinguishing characteristic of a POS plan?

The distinguishing characteristic of a POS plan is that it combines elements of both Health Maintenance Organization (HMO) and Preferred Provider Organization (PPO) plans. A POS plan allows members to choose between receiving care from a network of preferred providers (like an HMO) or going outside the network for care (similar to a PPO). This flexibility enables members to have the option to access specialists without requiring a referral if they choose to go outside the network.

In contrast, other options do not accurately represent a POS plan. For example, while it is true that some plans may not require upfront payments, this characteristic alone does not define a POS plan specifically. Additionally, POS plans offer coverage beyond just preventive services. They typically cover a wide range of medical services, not just preventative ones. Lastly, while referrals may be required when using network services, the defining attribute of a POS plan lies primarily in its structural combination of both HMO and PPO features.