ABSTRACT: American veterans are a population that suffer from both context specific stressors as well as many population-specific major-life events. The present exploratory study utilises a longitudinal cohort of 1230 U.S. veterans surveyed from February 2020 through February 2021. We sought to understand heterogeneity in perceived stress, using growth mixture modelling, over this time period, how COVID-specific factors such as negative reactions to the pandemic, loneliness, and employment disruptions influence perceived stress trajectories, and how veterans vary across distal outcomes including posttraumatic stress disorder (PTSD), pain, depression, sleep problems, physical health, and alcohol use disorder. Results revealed a 4-class solution: Stable High, Stable Low, Steady Increasing, and Steady Decreasing classes. In terms of COVID specific factors, negative reactions to COVID were consistently associated with perceived stress for those in the Stable High and Steady Increasing classes whereas loneliness was associated with stress trajectories for all emergent classes. Finally, in terms of our distal outcomes, results showed a relatively robust pattern with veterans in the Stable High or Steady Increasing classes reporting worse scores across all outcomes including PTSD, pain, sleep problems, physical health, depression, and alcohol use disorder. Understanding the interplay between existing vulnerabilities, ongoing stressors, and behavioural health outcomes among veterans is crucial for prevention and intervention efforts.