Objective <p>The spillover effects of health issues are widespread, may be especially for vulnerable groups who are more dependent on their families. While the importance of spillovers in resource allocation decisions is increasingly recognized, the empirical evidence in China is generally limited. This study aimed to estimate the health spillover effects among household members of adolescents (8–17&#xa0;years) and elderly individuals (≥ 60&#xa0;years) with health issues in China.</p> Methods <p>Data were obtained from the 2023 Health Service Survey conducted in Tianjin, one of China’s four municipalities. Health issues included diagnosed chronic disease, illness within two weeks, unintentional injuries or any hospitalizations in the past year. The absolute spillover effects were evaluated by comparing EQ-5D-5L utility values between household members exposed/unexposed to adolescent/elder individuals with health issues. The relative spillover effects were estimated using the ordinary least square regression (OLS) model.</p> Results <p>More household members exposed to adolescents with health issues reported anxiety/depression problems than those unexposed (8.6% vs. 3.1%, <i>p</i> &lt; 0.05), though no significant utility difference was found (adjusted Coef. = 0.055, <i>p</i> &gt; 0.1, SE = 0.291). Exposure to elderly individuals with health issues was associated with increased reports of pain/discomfort (20.7% vs. 14.7%, <i>p</i> &lt; 0.05) and anxiety/depression (8.8% vs. 4.6%, <i>p</i> &lt; 0.05), with a significant spillover effect of 0.044 (<i>p</i> &lt; 0.05, SE = 0.022).</p> Conclusions <p>Focusing on adolescents and the elderly with health issues, this study offers population-based evidence of health spillover effects within Chinese households. These findings support the existence of spillover effects in the Chinese context and offer benchmark estimates to inform public health policy.</p>