Which type of organization provides comprehensive health care services on a prepayment basis?

The Health Maintenance Organization (HMO) operates by providing a wide range of health care services to its members on a prepayment basis. This model is designed to emphasize preventive care and overall health management, allowing members to access services through a network of providers in return for a fixed monthly fee. Members typically choose a primary care physician who coordinates their care and refers them to specialists within the HMO network, promoting a more integrated approach to health care.

In contrast, the other organizations mentioned function differently. Preferred Provider Organizations (PPOs) offer more flexibility in choosing healthcare providers but do not operate on a prepayment basis and usually involve higher costs for out-of-network services. Independent Practice Associations (IPAs) consist of independent physicians who provide care on a contractual basis with insurance plans, but they may not cover the comprehensive range of services typical of HMOs. Accountable Care Organizations (ACOs) focus on coordinated care and improving quality while reducing costs, but they don't specifically follow the prepayment structure characteristic of HMOs.