My wife is 78 and she has had type 2 diabetes for many years. Her doctor tells her to get an A1C test every three months. Recently, Medicare has denied the claim. Medicare says that A1C is not a covered service and not deemed a medical necessity. I often read about A1C in Diabetes Forecast—that it is very important for preventing diabetes complications, such as problems with the kidneys, nerves, and eyes, or cardiovascular events. So, how then can Medicare decide that frequent A1C testing is not a medical necessity? The annual cost for A1C is too expensive ($64.85 per test, four times a year). I might just check A1C twice a year.
Chen-Nang Tai, Bayside, N.Y.

Robert Gabbay, MD, PhD, responds: You are right that A1C is a very important measure of how a person's diabetes is doing. It is the best indicator and determinant of risk for developing complications of diabetes, as you describe. Since A1C averages blood glucose for the past three months, it gives a good measure of blood glucose control over time. It's important to measure A1C in addition to your regular blood glucose tests.

ADA recommends at least two A1C tests a year for patients who are meeting treatment goals and have stable blood glucose. For patients who don't, quarterly A1C tests are
appropriate. In most cases, Medicare should cover A1C tests every three months for patients with diabetes. But if you get an A1C test as little as a day before the three-month mark, then it's deemed unnecessary and Medicare will not cover the cost of the test. Be careful to check this information before scheduling your appointment.