Affective experiences are key components of subjective well-being with important implications for health. However, little is known about heterogeneous longitudinal affect trajectories and their links to survival. This study identified joint trajectory subgroups based on 18-year changes in positive affect (PA) and negative affect (NA) and examined their differential associations with mortality risk. Participants were 3,250 adults (aged 39-93 years) from the Midlife in the U.S. study assessed over three waves (1995-2013). Parallel growth mixture modeling revealed three subgroups: (a) improving (increasing PA, decreasing NA), (b) deteriorating (decreasing PA, increasing NA), and (c) flourishing (high, stable PA, low, stable NA). Adjusting for baseline demographic and health covariates, Cox proportional-hazard results showed the improving group had the lowest mortality risk (HR = 0.82, 95% CI [0.35, 1.32]) and the deteriorating group had the highest mortality risk (HR = 1.86, 95% CI [1.34, 3.55]), relative to flourishing. These findings highlight the importance of modeling multidimensional trajectories of affective well-being and their heterogeneous links to survival. (PsycInfo Database Record (c) 2024 APA, all rights reserved).