Purpose <p>The aim of the current study was to investigate if transdiagnostic factors, such as anxiety sensitivity, perceived control over anxiety-related events, and distress tolerance, were associated with posttraumatic stress symptoms over time during the COVID-19 pandemic. To accomplish this aim, a secondary analysis of existing data using longitudinal growth curves was used.</p> Methods <p>Participants (<i>N</i> = 575) were recruited from Amazon Mechanical Turk (MTurk) at the height of the COVID-19 pandemic (March 2020–September 2020). The sample consisted of mostly White (71.1%) males (57.2%) with an average age of 38.7 (<i>SD</i>_age = 12.1).</p> Results <p>The effect of anxiety sensitivity for posttraumatic stress symptoms at baseline to 6&#xa0;months later was small and positive and statistically significant for the linear slope (intercept slope =.87, linear slope = −.29, and quadratic slope =.17). The effect of distress tolerance on posttraumatic stress symptoms from baseline to 6&#xa0;months later was small and negative (intercept slope = −.02, linear slope =.14, and quadratic slope = −.10). The effect of perceived control over anxiety-related events on posttraumatic stress symptoms from baseline to 6&#xa0;months later was small and negative (intercept slope =.02, linear slope = −.28, and quadratic slope =.25).</p> Conclusions <p>These findings provide support of perceived control over anxiety-related events on resilience for posttraumatic stress symptoms in the context of COVID-19 pandemic, which can inform mental health programming for future viral outbreaks.</p>