The proposed study explores the impact of simple mailed interventions directed toward patients or providers on the rates of use of ACE inhibitors, Blood pressure lowering drugs and Cholesterol lowering therapies – the ABCs - by older patients with DM. We hypothesize that: 1) mailed interventions including prescriber feedback can increase the ABCs relative to controls; 2) that interventions directed toward patients and providers are equally effective in promoting the ABCs among patients selected to receive the intervention and 3) that interventions directed towards clusters of patients within a physician’s practice will also change the care provided by those physicians to their other patients, in the absence of any direct intervention to the physician.