<b><i>Introduction:</i></b> Adjustment disorder is frequently diagnosed in clinical practice; however, the course of adjustment disorder over time has not yet been studied extensively. <b><i>Methods:</i></b> This longitudinal study was one of the first that aimed to analyze trajectories of adjustment disorder symptoms in a 12-month follow-up among a high-risk community sample (<i>n</i> = 205) exposed to various stressors. Adjustment disorder symptoms were measured at baseline and 12-month follow-up with the Brief Adjustment Disorder New Module based on the definition of adjustment disorder provided in the 11th Edition of International Classification of Diseases (ICD-11) released in 2018 by the World Health Organization (WHO). <b><i>Results:</i></b> A latent transition analysis of adjustment symptoms identified four distinct trajectories: “high symptom,” “recovery,” “onset,” and “low symptom.” We found 46% of ICD-11 adjustment disorder at baseline, and 29% of the sample was classified as having a high-symptom adjustment symptom profile. The high-symptom profile was predicted by ongoing stressors, female gender, and higher education. <b><i>Conclusion:</i></b> Study findings indicate that adjustment disorder among high-risk samples, in particular, those exposed to ongoing stressors, could have a high-symptom course over 12 months.