Final answer:
To see a specialist in an HMO, a referral from a primary care physician is necessary due to their role as gatekeepers, aiming to control costs and coordinate patient care efficiently within the system's fixed budget.
Step-by-step explanation:
When attempting to see a specialist through a Health Maintenance Organization (HMO), a patient must obtain a referral from their primary care physician (PCP). Unlike the fee-for-service health financing system, where providers are compensated for each service provided, HMOs operate on a fixed payment structure per enrollee, tasked with managing each patient's care efficiently within this capitated budget. This system intends to contain costs and incentivize preventive care.
A referral is required because HMOs are designed to control costs and ensure the appropriate use of specialist services. The PCP acts as a gatekeeper, coordinating care and preventing unnecessary specialist services that may lead to increased healthcare spending. Adverse selection presents a challenge in insurance markets when there is asymmetric information between insurance buyers and the insurance company, causing imbalance and potential financial risk for the insurer.