This meta-analytic review investigated interventions for transition-age youth diagnosed with autism, intellectual disability, or extensive support needs. Nineteen group design studies with 215 effect sizes met inclusion criteria. A robust variance estimation procedure that accounts for the clustering effect sizes within studies was used to synthesize effect sizes within each intervention and outcome type. Occupational Therapy/Physical Therapy interventions have significant and positive effects on gross motor outcomes (g = 0.73, p < 0.01). All remaining interventions and outcomes could not be synthesized due to a limited number of studies, but are further described in a narrative manner. Recommendations for future research include improving the methodological quality of intervention studies and further analyzing the effects of interventions for transition-age youth.