Child maltreatment is a significant public health problem, with estimates suggesting that as many as one in four children are exposed to maltreatment during their lifetimes. Child maltreatment has been associated with negative consequences including impacts on physical and mental health. Efforts have been made to codify the impacts of child maltreatment on children’s development via the proposed diagnosis of Childhood Complex Posttraumatic Stress Disorder (Complex PTSD). The focus of Chapters 1 and 2 was the application of a data-driven approach to assessing the construct validity of the Childhood Complex PTSD diagnosis as currently specified using exploratory factor analysis and latent profile analysis. Results indicated that many symptoms specified by complex trauma theory meaningfully clustered into distinct factors, representing different areas of impairment in functioning that may be observed in children with chronic trauma exposure. Specific symptoms constituting each area of impairment diverged significantly from the theoretical criteria in several cases, and some symptoms specified by the theory of complex trauma were not meaningfully related to any factor. Notably, a class with impairment across all proposed domains of functioning was not observed in the data, suggesting that changes in the diagnostic conceptualization of Childhood Complex PTSD may be warranted. Additionally, further assessment of the most effective ways to serve trauma-exposed populations is critical. Children experiencing homelessness are at increased risk for exposure to potentially traumatic events. Despite the existence of evidence-informed, trauma-informed care (TIC) interventions to mitigate the impacts of such trauma, families experiencing homelessness rarely receive TIC. Investigators used a community-based participatory research framework to complete 20 semi-structured qualitative interviews with shelter staff assessing the acceptability, appropriateness, and feasibility of implementing TIC in the family homeless shelter setting. Participants expressed generally positive attitudes toward TIC and viewed it as aligned with the mission of their organization, indicating strong support for acceptability and appropriateness. With regard to feasibility, participants identified unique context-specific barriers to which implementation strategies could be tailored.