Diabetes patients are generally encouraged to maintain A1C levels below 7 percent because good control of blood glucose decreases the risk of developing complications from the disease. Diabetes is diagnosed when A1C levels reach 6.5 percent or more, according to WebMD.
Some patients, particularly if they are susceptible to hypoglycemia or have a limited life expectancy, have target A1C levels above 7 percent. Diabetes patients should have their A1C levels tested two to four times per year, according to the National Institutes of Health. Regular testing allows doctors to respond quickly to elevated blood sugar levels, keeping the risk of complications in check.