This study evaluated a quality improvement initiative to implement a more coordinated transition process for adolescents with chronic illnesses moving from pediatric to adult-focused healthcare using the Six Core Elements framework. They found: 1) Teams reported improved implementation of transition processes over time, especially in transition readiness and transfer of care. 2) The proportion of patients transitioned from pediatric to adult providers doubled from 11% to 27% and the average time between last pediatric and first adult visit decreased from 232 to 146 days. 3) Providers felt the Six Core Elements provided a useful framework and regular meetings between pediatric and adult providers helped build trust to advance the transition process.