The Chronic Care Model (CCM) is a widely adopted approach to improving ambulatory care that has guided clinical quality initiatives in the United States and globally. Developed over a decade ago, the CCM aims to transform the delivery of care for chronic illnesses from reactive to proactive, planned, and population-based. It emphasizes six interrelated system changes to support patient-centered, evidence-based care, including self-management support, decision support, delivery system design, clinical information systems, health care organization, and community resources. Evidence since 2000 suggests that implementing the CCM leads to improved patient care and health outcomes. Studies show that practices redesigning care according to the CCM see better health outcomes, such as reduced hospitalizations and improved quality of life for patients with asthma and diabetes. However, some studies have found no significant improvements, possibly due to short follow-up periods, low participation rates, or contamination between intervention and control groups. The CCM is not a single intervention but a framework for practice redesign. While some studies show that implementing the CCM can lead to cost savings, the initial costs of implementation can be high. The CCM is not easily replicable and requires significant organizational changes. Research indicates that practices with higher performance often implement multiple CCM elements, but more research is needed to understand the effectiveness and cost implications of implementing the CCM in different settings. The CCM has been used in various quality improvement initiatives, including the Health Disparities Collaboratives (HDCs) and the Improving Chronic Illness Care (ICIC) Collaboratives. These initiatives have shown that while process improvements are often seen quickly, intermediate outcomes may take longer to materialize. The CCM is also part of current patient-centered medical home models. Despite its potential, the CCM requires further research to fully understand its effectiveness, cost implications, and practicality in different healthcare settings. The evidence suggests that the CCM can improve care for chronic illnesses, but more research is needed to support its widespread implementation and to develop better tools for helping practices improve their systems.The Chronic Care Model (CCM) is a widely adopted approach to improving ambulatory care that has guided clinical quality initiatives in the United States and globally. Developed over a decade ago, the CCM aims to transform the delivery of care for chronic illnesses from reactive to proactive, planned, and population-based. It emphasizes six interrelated system changes to support patient-centered, evidence-based care, including self-management support, decision support, delivery system design, clinical information systems, health care organization, and community resources. Evidence since 2000 suggests that implementing the CCM leads to improved patient care and health outcomes. Studies show that practices redesigning care according to the CCM see better health outcomes, such as reduced hospitalizations and improved quality of life for patients with asthma and diabetes. However, some studies have found no significant improvements, possibly due to short follow-up periods, low participation rates, or contamination between intervention and control groups. The CCM is not a single intervention but a framework for practice redesign. While some studies show that implementing the CCM can lead to cost savings, the initial costs of implementation can be high. The CCM is not easily replicable and requires significant organizational changes. Research indicates that practices with higher performance often implement multiple CCM elements, but more research is needed to understand the effectiveness and cost implications of implementing the CCM in different settings. The CCM has been used in various quality improvement initiatives, including the Health Disparities Collaboratives (HDCs) and the Improving Chronic Illness Care (ICIC) Collaboratives. These initiatives have shown that while process improvements are often seen quickly, intermediate outcomes may take longer to materialize. The CCM is also part of current patient-centered medical home models. Despite its potential, the CCM requires further research to fully understand its effectiveness, cost implications, and practicality in different healthcare settings. The evidence suggests that the CCM can improve care for chronic illnesses, but more research is needed to support its widespread implementation and to develop better tools for helping practices improve their systems.