People with depression often underutilize mental health care. This study was conceived as a first step toward a clinical decision support tool that helps identify patients who are at higher risk of underutilizing care. The primary goals were to (a) describe treatment utilization patterns, early termination, and return to care; (b) identify factors associated with early termination of treatment; and (c) evaluate the accuracy of regression models to predict early termination. These goals were evaluated in a retrospective cohort analysis of 108,457 U.S. veterans who received care from the Veterans Health Administration between 2001 and 2021. Our final sample was 16.5% female with an average age of 34.5. Veterans were included if they had a depression diagnosis, a positive depression screen, and received general health care services at least a year before and after their depression diagnosis. Using treatment quality guidelines, the threshold for treatment underutilization was defined as receiving fewer than four psychotherapy sessions or less than 84 days of antidepressants. Over one fifth of veterans (21.6%) received less than the minimally recommended care for depression. The odds of underutilizing treatment increased with lack of Veterans Administration benefits, male gender, racial/ethnic minority status, and having received mental health treatment in the past (adjusted OR > 1.1). Posttraumatic stress disorder comorbidity correlated with increased depression treatment utilization (adjusted OR < .9). Models with demographic and clinical information from medical records performed modestly in classifying patients who underutilized depression treatment (area under the curve = 0.595, 95% CI [0.588, 0.603]). Most veterans in this cohort received at least the minimum recommended treatment for depression. To improve the prediction of underutilization, patient factors associated with treatment underutilization likely need to be supplemented by additional clinical information. (PsycInfo Database Record (c) 2024 APA, all rights reserved).