Diagnostic criteria (e.g., Diagnostic and Statistical Manual of Mental Disorders, 4th ed.) for posttraumatic stress disorder (PTSD) posit three symptom clusters including reexperiencing, avoidance/numbing, and hyperarousal. Factor analytic studies have suggested several alternative models of PTSD symptomatology. It is uncertain whether these new models are widely generalizable as most studies have relied on relatively select treatment seeking samples (e.g., combat veterans). To address this limitation, confirmatory factor analysis was applied to symptom data from National Comorbidity Survey respondents with a lifetime history of PTSD (n = 429). Several models were tested. The model comprised of four intercorrelated factors (reexperiencing, avoidance, numbing, and hyperarousal) received the strongest support, but did not meet all the goodness-of-fit criteria. A follow-up principal-components analysis yielded a four-factor solution, with factors representing dysphoria, cued reexperiencing and avoidance, uncued reexperiencing and hyperarousal, and trauma-related rumination. The theoretical and clinical implications of these findings are discussed.