Inhibitors of the renin-angiotensin-aldosterone system (RAAS) prescribed at maximally tolerated doses are a critical part of clinical practice guidelines for management of patients with chronic kidney disease (CKD), congestive heart failure with reduced ejection fraction, and a recent myocardial infarction. These drugs interfere with the hormonal system regulating kidney excretion of potassium and commonly cause hyperkalemia. Patients at greatest risk for this complication are those with CKD who commonly have diabetes and/or coexisting cardiovascular disease.