Type 2 diabetes mellitus (T2DM) is a common chronic metabolic condition. Before receiving this diagnosis, persons typically have a long period of prediabetes. There is good evidence that T2DM can often be prevented or delayed by means of lifestyle interventions (39%-71%), medications (28%-79%), or metabolic surgery (75%). However, despite consistent data demonstrating their efficacy, these tools are underused, and knowledge about them among primary care physicians is limited. In an effort to engage physicians in addressing this public health crisis more effectively, the authors reviewed the evidence that T2DM can be prevented or delayed in persons at risk.