National Healthcare Security Administration (NHSA) of China routinely evaluates and modifies insurance coverage rates for drugs and services within the Basic Medical Insurance (BMI) system to balance patients essential support and healthcare budget. This study examines how insurance impacts patient behaviors and physicians’ decision-making. Using outpatient data from one of the largest regional hospitals in Liaoning, China, we employ logistic regression to examine the impacts of insurance coverage rates on unclaimed prescription rates, an indicator of medication nonadherence. Additionally, we apply multivariate regression to assess how physicians adapt their prescribing practices in response to insurance coverage rate adjustments. Our findings indicate that drugs are less likely to be unclaimed compared to services, as patients often prioritize symptom-relief medications over diagnostic tests when their insurance allowances are about to be exhausted. Widely used drugs and services are less likely to be unclaimed. However, higher total prescription charges increase the likelihood of unclaimed prescriptions, except for rural patients with service prescriptions. The study demonstrates variations in unclaimed prescription rates based on patients’ characteristics and prescription features. The effects of changes in insurance coverage rates on prescription volumes vary depending on factors such as the medical center’s location (urban or rural), drug category, and patient insurance status, highlighting the necessity for context-specific insurance policies. These findings suggest that NHSA should consider tailored insurance strategies to best utilize the healthcare budget - increasing coverage rates alone may not address all patient needs effectively.