Within criminology, life course theory and research have linked positive role transitions (e.g., marriage, parenthood, and employment) with criminal desistance over time. Simultaneously, studies suggest that high-risk offenders are unlikely to enter or remain committed to such transitions, challenging interventions based on life course principles. Prison-based therapeutic communities (TCs) offer a potential exception to this pattern and have proven particularly effective at reducing drug dependence and criminal recidivism by integrating inmates into positive peer environments. From a life course perspective, these programs emphasize human agency and linked lives as mechanisms for behavioral change. However, the peer-network processes underlying TC programming remain virtually untested. To fill this void, this chapter applies life course and social network perspectives to understand prison TC processes and demonstrate the feasibility and promise of our approach with preliminary findings from a cross-sectional study of a small TC (N = 20) in a maximum-security men’s prison.