A new information campaign of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health, highlights the importance of using accurate methods to test hemoglobin A1c in people with diabetes who have sickle cell trait or other inherited forms of variant hemoglobin. The specific needs for testing blood glucose control in these patients are explained in two booklets, “Sickle Cell Trait and Other Hemoglobinopathies and Diabetes: Important Information for Physicians” and “For People of African, Mediterranean, or Southeast Asian Heritage: Important Information about Diabetes Blood Tests” from NIDDK’s National Diabetes Information Clearinghouse at www.diabetes.niddk.nih.gov.