<p>Access to quality essential healthcare services is a fundamental right for all residents. However, the unequal allocation of healthcare resources affects patients' accessibility to care, thereby influencing their healthcare choices. Utilizing health insurance administrative data and employing a difference-in-differences (DID) model, this study examines the impact of China’s healthcare resource allocation reform on patients’ healthcare choices. The findings reveal that increased investment in rural healthcare resources significantly reduces the proportion of residents seeking medical services outside their counties, alleviates patients’ medical burden, and enhances healthcare quality. Notably, these improvements primarily benefit patients with common diseases, while the impact on those with rare diseases remains less pronounced. These results underscore the importance of strengthening the comprehensive capabilities of county-level hospitals and prioritizing high-quality resource allocation in rural areas as key directions for future reforms in healthcare system.</p>