A1C Basics

A1C Target

For people without diabetes, about 4-6 percent of hemoglobin is glycosylated, so an A1C of 4-6 percent is considered normal. An A1C greater than 6.5 percent is now considered one indication for a diagnosis of diabetes. For people with diabetes, an A1C of less than 7 percent reduces risk of the heart, eye, kidney, and nerve damage that can accompany diabetes. Many doctors advise people living with diabetes to aim for an A1C as near to normal as possible. You should decide your specific target with your doctor or health-care provider.

Note: A study suggests the A1C test is inaccurate for people undergoing hemodialysis because of kidney disease or failure. The A1C reading may be falsely reduced due to shortened red blood cell survival and red blood cell transfusions. Source: Kidney International, February 2008

How Often to Get an A1C Test

The American Diabetes Association (ADA) recommends an A1C test at least twice a year if your blood glucose control is stable and within target. You may want to have the test more frequently (such as every three months) if your diabetes-treatment plan is under adjustment, you have diabetes and are considering pregnancy, or you are dependent on insulin, which includes people with type 1 diabetes.