["Journal of Traumatic Stress, Volume 39, Issue 2, Page 225-238, April 2026. ", "\nAbstract\nTrauma‐focused cognitive behavioral therapy (TF‐CBT) is an evidence‐based treatment widely used for youth experiencing symptoms related to posttraumatic stress disorder (PTSD). This study used both cross‐sectional and cross‐lagged panel network (CLPN) analyses to examine changes in PTSD symptom networks following TF‐CBT and explore their clinical relevance. Using data from a statewide implementation of TF‐CBT, we constructed PTSD symptom networks for 652 youth (Mage = 12.47 years, 57.5% girls, 21.9% youth of color) who completed TF‐CBT and provided both pre‐ and posttreatment data. At pretreatment, central symptoms included detachment, psychological and physiological reactions, and negative cognitions. Although the overall connectivity between symptoms significantly increased after treatment, p = .003, the symptom structure remained stable. CLPN analyses identified symptoms with high predictive influence (out‐expected influence [out‐EI]: physiological reactions, negative emotional state, and diminished interests) and susceptibility to influence (in‐EI: internal and external avoidance, nightmare, detachment). Pretreatment centrality, B = 0.07, p < .001, and in‐EI, B = 0.72, p = .003, but not out‐EI, B = −0.04, p = .633, were associated with larger overall pre–post symptom reductions, controlling for baseline symptom severity. Improvements in symptoms with high pretreatment centrality, B = 1.17, p = .011), and in‐EI centrality, B = 0.34, p = .568, but not out‐EI centrality, B = 0.34, p = .568, were related to posttreatment psychosocial functioning over and above peripheral symptoms. These results offer preliminary evidence on how symptoms change during treatment, providing insight for understanding change mechanisms of TF‐CBT and further refining youth trauma treatment.\n"]