Posttraumatic stress disorder (PTSD) often presents with comorbidities and can result in functional impairment. Veterans and service members report PTSD at higher rates than civilians, which represents a public health concern among those who have served or are serving in the military. Prior reviews of evidence-based treatments for PTSD demonstrate smaller effect sizes for veterans and service members than for civilians. One line of investigation that may contribute to our understanding in this area is developmental trajectory research. Understanding predictors of different symptomatic trajectories compared to resilient trajectories and vice versa may help clinicians better tailor evidence-based conceptualizations, treatments, and change agents to the individual, facilitate prevention efforts, and embark on a process-based, flexible, cognitive-behavioral approach that is patient-centered. The current systematic review examined predictors of both resilient (i.e., compared to heterogeneous symptomatic trajectories) and variable symptomatic trajectories (i.e., compared to resilient and/ or other symptomatic trajectories) in veterans and service members. Twenty-seven studies met inclusion criteria. Across all included studies reporting percentages of resilience trajectories (i.e., including some studies that used the same data sets and/or samples), 73.4% reported a resilience trajectory, while the remaining 26.6% encompassed heterogeneous symptomatic trajectories on average. Predictors are presented and discussed, in