What counts as prediabetes?
Written and medically reviewed by Zahraa Sater, M.D., M.P.H.
Reviewed August 12, 2026 · Next review due August 12, 2028
Short answer
Prediabetes is defined by the 2026 ADA Standards of Care as a fasting plasma glucose of 100 to 125 mg/dL, a two hour plasma glucose of 140 to 199 mg/dL on a 75 g oral glucose tolerance test, or an A1C of 5.7 to 6.4 percent. Any one of the three qualifies.
Prediabetes is a label for glucose values that sit above normal and below the diabetes thresholds. The 2026 ADA Standards of Care set three ways in, and any single one is enough: fasting plasma glucose 100 to 125 mg/dL, two hour plasma glucose 140 to 199 mg/dL during a 75 g oral glucose tolerance test, or A1C 5.7 to 6.4 percent.
The three tests do not always agree
People are often surprised that a normal fasting glucose sits next to an A1C of 5.9 percent, or the reverse. The three tests measure different things: fasting glucose is one moment in a fasted state, the two hour value is a stress test of glucose handling, and A1C reflects average glycemia over roughly three months. Impaired glucose tolerance on the two hour test is frequently the first abnormality to appear, and it is missed entirely if only fasting blood is drawn.
| Test | Normal | Prediabetes | Diabetes |
|---|---|---|---|
| Fasting plasma glucose | Below 100 mg/dL | 100 to 125 mg/dL | 126 mg/dL or above |
| Two hour plasma glucose, 75 g OGTT | Below 140 mg/dL | 140 to 199 mg/dL | 200 mg/dL or above |
| A1C | Below 5.7 percent | 5.7 to 6.4 percent | 6.5 percent or above |
How common prediabetes is
Prediabetes is not a rare finding. The CDC estimated 115.2 million US adults had prediabetes in 2023, and 52.1 percent of people aged 65 and older. Volume matters here because it changes how the label should be read. Prediabetes marks a risk state shared by a very large share of adults, not a personal failure and not an inevitable path to insulin injections.
Who should be tested
The US Preventive Services Task Force recommends screening for prediabetes and type 2 diabetes in adults aged 35 to 70 years who have overweight or obesity, a grade B recommendation. It advises considering earlier screening in people from higher risk groups and in those with a family history of diabetes, previous gestational diabetes or polycystic ovary syndrome. Where glucose is normal, screening every three years is described as reasonable.
If a result lands in the prediabetes range, ask for it to be confirmed, and ask which of the three tests was abnormal, because that shapes what to track next. Then ask for a plan with a number in it: a weight target, an activity target, and a repeat test date. The clinically meaningful question is not whether you carry the label but whether the number is moving.
The clinical detail
The 2026 ADA criteria for diabetes are fasting plasma glucose 126 mg/dL or above after at least eight hours without caloric intake, two hour plasma glucose 200 mg/dL or above during a 75 g oral glucose tolerance test, A1C 6.5 percent or above using an NGSP certified method, or a random plasma glucose 200 mg/dL or above in a person with classic symptoms of hyperglycemia or hyperglycemic crisis.
In the absence of unequivocal hyperglycemia, a diagnosis requires two abnormal results, either two different tests from the same sample or the same test repeated on a separate occasion. Discordant results should prompt repeating the abnormal test. Impaired fasting glucose and impaired glucose tolerance can occur separately, and each independently predicts progression to type 2 diabetes.
Written and medically reviewed by Zahraa Sater, M.D., M.P.H.
Reviewed August 12, 2026 · Next review due August 12, 2028
Sources
- 2. Diagnosis and Classification of Diabetes: Standards of Care in Diabetes 2026. American Diabetes Association. PMID 41358893
- Screening for Prediabetes and Type 2 Diabetes: Recommendation Statement. US Preventive Services Task Force
- National Diabetes Statistics Report. Centers for Disease Control and Prevention
- Insulin Resistance and Prediabetes. National Institute of Diabetes and Digestive and Kidney Diseases
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