Forgiveness-based group treatments to address interpersonal hurts have been shown to be efficacious across a range of therapy models (Wade, Hoyt, Kidwell, & Worthington, 2014). However, little is known about how treatment and individual characteristics may interact in predicting outcomes. The present study examined a sample of 162 community adults randomly assigned to three treatment conditions; an 8-week REACH Forgiveness intervention (Worthington, 2006), an 8-week process group, and a waitlist control. Hierarchical linear modeling (HLM) indicated that the forgiveness-based treatment was more effective than the waitlist control across a range of forgiveness-related constructs but no more effective than the process condition. Furthermore, attachment avoidance and anxiety interacted with treatment type to predict certain outcomes, indicating that the REACH Forgiveness model may be more helpful for promoting forgiveness with insecurely attached individuals.