This article demonstrates effects on utilization of a clinical transformation: changing locus of care from a dedicated sickle cell day unit to an approach that “fast-tracks” patients through the emergency department (ED) into an observation unit with 24/7 access. Retrospective quantitative analyses of claims and Epic electronic medical record data for patients with sickle cell disease treated at Thomas Jefferson University (inpatient and ED) assessed effects of the clinical transformation. Additionally, case studies were conducted to confirm and deepen the quantitative analyses. This study was approved by the Thomas Jefferson University Institutional Review Board. The quantitative analyses show significant decreases in ED and inpatient utilization following the transformation. These effects likely were facilitated by increased observation stays. This study demonstrated the impact on utilization of transformation in care (from dedicated day unit to an approach that fast-tracks patients into an observation unit). Additional case studies support the quantitative findings.