What is the primary function of an HMO?

The primary function of a Health Maintenance Organization (HMO) is to operate on a prepaid health service model. This means that members typically pay a fixed monthly fee, which grants them access to a range of healthcare services. This model is designed to promote preventive care and reduces overall healthcare costs by encouraging members to seek care early and regularly instead of waiting until issues become severe. The HMO coordinates care among its providers, which is often delivered within a network of doctors and hospitals, which helps in managing the overall health of its members.

In contrast, the other options focus on specific aspects of healthcare delivery or administration that do not capture the essence of an HMO's primary function. Emergency services, while important, are not exclusive to HMOs and do not define their purpose. Similarly, while HMOs may include specialty care, it is not their primary function. Facilitating insurance claims processing is typical of all types of health insurers but does not uniquely describe the operational model of an HMO. Therefore, the focus on the prepaid health service model correctly identifies the main characteristic that distinguishes HMOs in the healthcare landscape.