Asian Americans, currently the most rapidly expanding racial group in the USA, are experiencing persistent mental health inequities. These inequities are particularly pronounced during adolescence, highlighting the critical need for dedicated focus on this demographic. Social support is a key shield against mental distress among these adolescents, yet little research has examined the collective impact of multiple sources of support over time, across developmental stages, and for different ethnic subgroups. Drawing on the integrated conceptual framework, this longitudinal study is the first to our knowledge to examine how support from families, religious organizations, and schools together predicts mental health over time across adolescents’ developmental stages. We further examined how these relationships may be moderated by age groups, distinguishing between the early adolescence cohort and the middle adolescence cohort. Data were from the Midwest Longitudinal Study of Asian American Families (MLSAAF) project that survey-interviewed 378 Filipino American and 408 Korean American adolescents (Mage = 15 years). Findings reveal that family support consistently buffers against mental distress throughout adolescence for both groups. Religious support distinctly aids Filipino American early adolescents, while school support notably benefits early adolescents regardless of ethnicity. These findings emphasize the universal protective effects of social support, while also highlighting the nuanced ways that developmental stage and ethnicity may influence how different sources of support impact mental health. This underscores the need for developmentally and culturally sensitive mental health strategies for Asian American adolescents.