Since 1989, international efforts to end protracted conflicts have included sustained investments in the disarmament, demobilization, and reintegration (DDR) of combatants. Yet while policy analysts have debated the factors that contribute to successful DDR programs and scholars have reasoned about the macro conditions that facilitate successful peace building, little is known about the factors that account for successful reintegration at the micro level. Using a new dataset of ex-combatants in Sierra Leone, this article analyzes the individual-level determinants of demobilization and reintegration. Past participation in an abusive military faction is the strongest predictor of difficulty in achieving social reintegration. On economic and political reintegration, we find that wealthier and more educated combatants face greater difficulties. Ideologues, men, and younger fighters are the most likely to retain strong ties to their factions. Most important, we find little evidence at the micro level that internationally funded programs facilitate demobilization and reintegration.