Researchers sought to examine whether there are patterns of oral hypoglycemic-agent adherence among primary-care patients with type 2 diabetes that are related to patient characteristics and clinical outcomes. Longitudinal analysis via growth curve mixture modeling was carried out to classify 180 patients who participated in an adherence intervention according to patterns of adherence to oral hypoglycemic agents across 12 weeks. Three patterns of change in adherence were identified: adherent, increasing adherence, and nonadherent. Global cognition and intervention condition were associated with pattern of change in adherence (p < .05). Patients with an increasing adherence pattern were more likely to have an Hemoglobin A1c) < 7%; adjusted odds ratio = 14.52, 95% CI (2.54, 82.99) at 12 weeks, in comparison with patients with the nonadherent pattern. Identification of patients with type 2 diabetes at risk of nonadherence is important for clinical prognosis and the development and delivery of interventions.