Our study examines the impact of informal care on healthcare utilization, focusing on caregiver types, urban-rural, and gender differences. Analyzing data from the China Health and Retirement Longitudinal Study and using fixed effects models, we discovered complementary effects between informal care and healthcare. Specifically, spousal care increased inpatient care use, adult child care boosted both inpatient and outpatient use, and dual care from children and spouses showed the most significant impact on healthcare use. The association between informal care and healthcare use varied across gender or urban-rural residence. Our findings highlight the importance of caregivers in accessing healthcare services.