Since the beginning of the Global War on Terror, almost three million children, spouses, and adult dependents have been directly affected by the deployment experiences of more than two million service members. This study examined the applicability of the Contextual Model of Family Stress (Boss, 2002) to a reintegrating military family sample (N = 228) by assessing the effects of external, military-related contextual factors (i.e., rank, component, combat exposure, length of time home post-deployment, and cumulative length of deployments) and internal contextual factors of boundary ambiguity and family and deployment-related ambivalence on family functioning. Quantitative data were taken from a national survey of service members from multiple branches of the United States military. A hierarchical regression analysis revealed that, as a whole, the addition of the military-related contextual factors, boundary ambiguity, and the ambivalence variables made a significant contribution to the prediction of family functioning, controlling for all previously entered variables. Service members from lower ranks and those who had been home for longer periods of time reported poorer family functioning. Higher degrees of boundary ambiguity and family ambivalence were also associated with poorer family functioning. The results from this study extend existing theoretical applications of the Contextual Model (Boss, 2002) to military families through the incorporation of boundary ambiguity and ambivalence. Findings will also inform interventions aimed at promoting family resilience in the military population during the post-deployment period.