Microaggression has been considered a form of stressor that negatively affects people with marginalized statuses. Research shows variability in how microaggression is measured, and the extent to which it is associated with adjustment outcomes. A new cube model was proposed to conceptualize microaggression across social groups, interpersonal and group-level interactions, and categories of incidents. Synthesizing findings from published and unpublished studies, this study was aimed to examine the relations between microaggression and adjustment outcomes. Meta-analyses quantified the study-level correlations between microaggression and various adjustment outcomes, and estimated the degree to which methodological and individual factors explained between-study variability. Using 72 independent study samples (N = 18,718), omnibus analysis with a random-effects model showed a statistically significant summary correlation between microaggression and adjustment outcomes (r = .20 (95% CI [.16-.23]), p < .001). Between-study variability (Q = 319.86, p < .001, τ2 = .01, I2 = 77.80%) was explained by gender, race, and publication status. Except for gender microaggression, racial, LGBTQ, and health status microaggressions were associated with adjustment outcomes. Microaggression was relatively more strongly associated with internalizing problems, stress/negative affect, and positive affect/adjustment than with externalizing problems and physical symptoms. Adjustment outcomes were more closely linked to interpersonal microaggression than group microaggression, and to microassault than microinsult and microinvalidation. Narrative reviews showed that very few studies tested whether microaggression predicted adjustment outcomes above and beyond overt discrimination and individual difference factors, and examined the indirect mechanisms that may link microaggression to adjustment outcomes. Limitations to the scope of this research synthesis and future research directions are discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).