Which of the following is NOT a type of private health insurance plan?

In the context of private health insurance plans, capitation is not a type of health insurance plan but rather a payment arrangement used within managed care systems. Under a capitation agreement, healthcare providers are paid a set amount per patient for a specified period of time, regardless of the number of services provided. This payment model is often used by various types of health plans, including HMOs (Health Maintenance Organizations) and PPOs (Preferred Provider Organizations), but it does not constitute a distinct insurance plan type like the others listed.

On the other hand, HMOs, PPOs, and POS (Point of Service) plans are all recognized types of private health insurance arrangements. Each of these plans has unique characteristics, such as provider networks and cost-sharing structures, which differentiate them from one another in how they provide coverage and access to healthcare services. Therefore, when assessing types of private health insurance plans specifically, capitation does not fit into that category, making it the correct choice in this context.