Women with co-occurring mental health and substance use disorders and trauma histories vary greatly in symptom severity and use of support services. This study estimated differential effects of an integrated treatment intervention (IT) across sub-groups of women in this population on services utilization outcomes. Data from a national study were used to cluster participants by symptoms and service utilization, and then estimate the effect of IT versus usual care on 12-month service utilization for each sub-group. The intervention effect varied significantly across groups, in particular indicating relative increases in residential treatment utilization associated with IT among women with predominating trauma and substance abuse symptoms. Understanding how IT influences service utilization for different groups of women in this population with complex needs is an important step toward achieving an optimal balance between need for treatment and service utilization, which can ultimately improve outcomes and conserve resources.