Tracing developmental pathways of immigrant-origin adolescents, this 3-year longitudinal study (2012-2015) examined within-person changes in cultural orientations and their consequences for school adjustment. Multivariate latent growth mixture modeling confirmed multiple pathways of integration, revealing variable acculturative changes along dual trajectories of heritage and mainstream orientations among European-origin (N = 592, M[subscript age] = 14.45, 55.1% boys) and Turkish- and Moroccan-origin adolescents (N = 1269, M[subscript age] = 14.70, 53.1% boys). Two trajectories for European-origin adolescents differed in "heritage" orientations (high decreasing and low increasing); for Turkish- and Moroccan-origin adolescents, three trajectories differed in "mainstream" orientations (high stable, low increasing, and high decreasing). Acculturative change affected aspects of later school adjustment: European-origin adolescents in high heritage orientation trajectories reported more belonging and emotional engagement; Turkish- and Moroccan-origin adolescents in high mainstream orientation trajectories reported more behavioral engagement.