The topics of quality improvement (QI) and patient safety have become important themes in health care in recent years, particularly in the emergency department setting, which is a frequent point of contact with the health care system for patients. In the first of three articles in this series meant as a QI primer for emergency medicine clinicians, we introduced the strategic planning required to develop an effective QI project using a fictional case study as an example. In this second article we continue with our example of improving time to antibiotics for patients with sepsis, and introduce the Model for Improvement. We will review what makes a good aim statement, the various categories of measures that can be tracked during a QI project, and the relative merits and challenges of potential change concepts and ideas. We will also present the Model for Improvement’s rapid-cycle change methodology, the Plan-Do-Study-Act (PDSA) cycle. The final article in this series will focus on the evaluation and sustainability of QI projects.