The specific strategies that individuals use to regulate their emotions have shown strong associations with various indices of well-being. However, theoretical accounts suggest that strategy use, and the associations between strategy use and well-being, may change across the life span. Attempts have been made to assess whether levels of strategy use, and the association between strategy use and well-being, change across development; however, studies typically do not take into account potential differences in base rates of item endorsement across the life span. Therefore, the current study had two objectives. First, we sought to examine whether relative ER strategy reliance, or the proportional degree to which an individual relies on various ER strategies, varied across three developmental periods: early adolescence, young adulthood, and adulthood. Second, we sought to identify whether the associations between relative strategy use and well-being differed significantly across these developmental periods. Results showed that relative reliance on distraction, rumination, relaxation, and suppression differed significantly across age groups. Moreover, results showed that the association between relative use of reappraisal and suppression interacted with age group to predict relationship quality. Relative strategy use and age did not interact significantly to predict anxiety and depressive symptoms. Theoretical and practical implications are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).