Function-based interventions, such as functional communication training, can be highly efficacious for reducing socially maintained destructive behavior (e.g., aggression, self-injury). Despite the efficacy of these interventions, destructive behavior often returns (i.e., relapse) following treatment. This chapter describes strategies to enhance durability during the assessment and treatment of socially reinforced destructive behavior. Durability encompasses both long-term maintenance of treatment effects and generalization across different conditions (e.g., settings, implementers). Promoting durability begins with ecologically valid assessments that closely mirror the natural environment and actively involve caregivers. Treatment strategies then focus on relapse mitigation, programming for generalization, and comprehensive caregiver training to ensure sustained implementation. Follow-up services provide ongoing monitoring and adaptation of treatment to evolving needs. We provide clinical case examples to illustrate the practical application of these strategies. By integrating these approaches, clinicians can improve the sustainability of treatment effects, ultimately reducing the likelihood of relapse and promoting lasting behavior change.