Obective: Although much has been studied regarding high-utilizing patients of medical services, no studies have been published regarding high-utilizing patients of integrated primary care behavioral health (PCBH) services. The primary purpose of the current study was to examine characteristics of high-utilizing patients of PCBH services and model adherence. The secondary purpose was to describe the process of conducting this research by clinicians in integrated care. Method: Data were obtained from electronic health records retrospectively for the study’s time period, 2007–2013, for the sample of all patients who met with the behavioral health consultation team during that time. Variables include demographics, diagnoses, involvement in additional services, and scores on a patient-complexity scale for a subset of patients. Chi-square analyses, t tests and logistic regression analyses were performed. Results: The results demonstrate significant associations between key demographic characteristics, use of population-based augmentation services (i.e., consulting psychiatry, care management, substance-abuse consulting), and high-utilizing status. Model adherence was maintained over time. Logistic regression analysis, controlling for high-utilizing status and number of visits, demonstrated a significant relationship between more complex diagnostic categories and behavioral health issues. Discussion: There are differences between high-utilizing patients and nonhigh-utilizing patients suggestive of increased clinical severity and appropriate use of services while maintaining PCBH model integrity. The use of the population-based augmentation services is associated with high-utilizer status, and reflects the ability of these services to target those patients who most need the clinical care.