The US Food and Drug Administration (FDA) is alerting patients who use diabetes devices and their caregivers of reports where users of continuous glucose monitors (CGMs), insulin pumps, automated insulin dosing systems, and other diabetes devices did not receive or did not hear alerts from their smartphones. A missed alert for a diabetes-related safety issue may lead to serious harm, including severe hypoglycemia (low blood sugar), severe hyperglycemia (high blood sugar), diabetic ketoacidosis (when the body does not have enough insulin to use blood sugar for energy), and death.