To ensure shared savings, an ACO must focus on keeping beneficiaries continuously assigned for those ACOs with retrospective assignment. Low churn rate enables the ACO to have lower variability in continuity of care, and therefore higher predictability of performance. Engaging the assigned population on a regular basis is critical in managing chronic conditions and ensuring quality metric compliance. Lastly, in order for the ACO to grow and thrive, they must understand why beneficiaries are losing attribution and how they can maintain attribution.