OBJECTIVE: The impact of number, length, and time between (i.e., "dwell time") deployments on long-term Diagnostic and Statistical Manual of Mental Disorders Fourth Edition posttraumatic stress disorder (PTSD) symptoms was examined in post-9/11 U.S. veterans. METHOD: This cross-sectional design includes data from 278 veterans participating in a larger longitudinal research program of postdeployment recovery. Measures included self-report questionnaires and the Clinician Administered PTSD Scale. RESULTS: Hierarchical regression was used to evaluate the independent contributions of deployment characteristics on long-term PTSD symptoms after controlling for demographics and combat exposure. As expected, dwell time was a significant predictor of long-term PTSD symptoms (β = - 0.17, p = .042; F5,108  = 8.21, ∆R2  = 0.03, p < .001). Follow-up analyses indicated that dwell time of less than 12 months was associated with significantly greater long-term PTSD symptoms than those deployed once or with dwell time greater than 12 months. CONCLUSION: In addition to combat exposure, time between deployments warrants clinical attention as an important deployment characteristic for predicting long-term PTSD symptoms.