Few natural disaster studies have assessed factors associated with posttraumatic stress disorder (PTSD) beyond a decade after trauma. Using North's disaster model as a framework, the aim of this study was to identify factors associated with clinically significant posttraumatic stress symptoms (CS-PTSDS) in avalanche survivors (n = 399) 16 years after the disaster. Completed self-report questionnaires were received from 286 (72%) survivors. CS-PTSDS were assessed with the Posttraumatic Diagnostic Scale. Predictors of CS-PTSDS in a multivariate analysis were secondary sequelae factors of lack of social support (adjusted relative risk [RR], 2.90; 95% confidence interval [CI], 1.37-6.13) and financial hardship in the aftermath of the trauma (adjusted RR, 2.47; 95% CI, 1.16-5.26). In addition, the community factor of providing assistance in the aftermath of the avalanche (adjusted RR, 1.95; 95% CI, 1.04-3.64) was inversely associated with CS-PTSDS. Screening for these factors may be useful in identifying those most vulnerable to developing chronic PTSD after this unique type of disaster.