As understanding about the pathophysiology of diabetes mellitus continues to evolve, it is important that its classification reflects the current state of knowledge. The eventual goal is that appreciation of the different forms of diabetes eventually will result in better treatment of hyperglycemia. Even more exciting is the fact that this appreciation is allowing us to enter the era of diabetes prediction and prevention. The current classification scheme of diabetes does not yet account for all of the types of diabetes seen in a typical diabetes clinic. Fig. 1 illustrates our current understanding of the pathophysiology of diabetes and separates the diabetes types into those used in the current classification scheme. Clearly, new classifications will be required as we learn more about the different types of diabetes.