Evidence guide
Prediabetes A1C Range: What 5.7%–6.4% Means
Understand the A1C prediabetes range, why a single number is not the whole story, and when repeat testing may be needed.
Published 2026-08-20 · Updated 2026-08-20 · Author: Prediabetes.Life
Short answer
An A1C from 5.7% through 6.4% is in the prediabetes range. Below 5.7% is generally considered normal, while 6.5% or above is in the diabetes range. A1C is useful, but diagnosis and follow-up should be handled by a clinician because test variation and some health conditions can affect the result.
What does A1C measure?
A1C estimates your average blood glucose over roughly the previous three months. Unlike fasting glucose, the test usually does not require fasting.
It is a screening and diagnostic tool, not a complete picture of metabolic health. A clinician may consider other glucose tests and your overall health history as well.
What do the A1C numbers mean?
| A1C | Common interpretation |
|---|---|
| Below 5.7% | Normal range |
| 5.7%–6.4% | Prediabetes range |
| 6.5% or above | Diabetes range; confirmation is generally required when there are no clear symptoms |
Does a higher A1C within the prediabetes range matter?
NIDDK notes that within the 5.7%–6.4% range, a higher A1C is associated with greater risk of developing diabetes. That does not mean a particular person will progress, and it does not replace an individualized clinical assessment.
Why might an A1C need to be repeated?
Laboratory measurements have normal variation, and certain conditions can make A1C less reliable. NIDDK advises confirmatory testing when an abnormal result is being used to diagnose diabetes and there are no clear symptoms.
- Ask whether your result was from a laboratory method appropriate for diagnosis.
- Tell your clinician about conditions or treatments that could affect red blood cells or hemoglobin.
- If A1C and another glucose test disagree, ask how your clinician plans to resolve the difference.
Sources
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