A1C of 5.7%: What It Means and What to Do Next
An A1C of 5.7% is the lowest value in the ADA’s prediabetes range (5.7% to 6.4%). It is not diabetes. It is a good reason to talk with your clinician about retesting and about a prevention program.
What 5.7% means
A1C shows your average blood sugar over roughly the last two to three months. The American Diabetes Association (ADA) calls 5.7% to 6.4% (39 to 47 mmol/mol) the prediabetes range. At 5.7%, the estimated average glucose is about 117 mg/dL (6.5 mmol/L). Try your own number in the A1C calculator.
Prediabetes means blood sugar is higher than the typical range but not high enough to be called diabetes. The ADA describes it as a stage where several approaches can delay type 2 diabetes. A single A1C is also only one piece of information: it can read a little high or low for reasons unrelated to blood sugar, such as anemia or certain hemoglobin variants.
What usually happens next
- Talk to your clinician. Ask whether to repeat the test or add a fasting glucose or glucose tolerance test. The ADA’s fasting prediabetes range is 100 to 125 mg/dL (5.6 to 6.9 mmol/L).
- Ask about a prevention program. The ADA recommends offering diabetes prevention programs to adults at high risk, and the CDC runs a national network of them.
- Plan the follow-up. The ADA suggests checking for diabetes at least once a year, with the schedule adjusted to your risk.
The CDC lifestyle change program
The CDC-recognized National Diabetes Prevention Program is a year-long program with a trained lifestyle coach, a CDC-approved curriculum and group support, offered in person and online. It covers everyday eating, physical activity and habits. To join, you generally need to be 18 or older, not have diabetes, not be pregnant, and meet a weight and risk requirement, such as a prediabetes-range blood test, a past gestational diabetes diagnosis or a high score on the CDC risk test. Medicare has its own version. Check the CDC pages in the sources list for current eligibility and to find a program near you.
What this page cannot tell you
It cannot tell you whether you have prediabetes. That is a clinical decision using lab tests, your history and your risk factors. It also cannot tell you what to eat or which medicines to take. Eating-pattern questions are best answered by a registered dietitian. If you want to see how a plate is built, our meal planner is coming soon.
Related: A1C chart, what an A1C of 6.5% means, how to lower A1C.
Frequently asked questions
Is an A1C of 5.7% diabetes?
No. The ADA lists 5.7% as the start of the prediabetes range. The diabetes range starts at 6.5%. Only a clinician can diagnose, using lab tests.
What blood sugar is an A1C of 5.7%?
About 117 mg/dL (6.5 mmol/L) as an estimated average over the last two to three months, using the ADAG formula.
Can an A1C of 5.7% go back down?
A1C can go up or down over time. What helps is a conversation with your clinician and, for many people, a structured lifestyle program. We do not promise any outcome, because results differ between people.
How often should I be retested?
The ADA suggests monitoring people with prediabetes for diabetes at least once a year, and adjusting how often based on individual risk. Ask your clinician what is right for you.
Information only, not medical advice. Your care team may set different targets for you, and only a lab test ordered by a clinician can diagnose diabetes or prediabetes. See our medical disclaimer.
Sources
- ADA Standards of Care in Diabetes—2026, Section 2: Diagnosis and Classification
- ADA Standards of Care in Diabetes—2026, Section 3: Prevention or Delay of Diabetes
- NIDDK: The A1C Test & Diabetes
- CDC: Lifestyle Change Program (National Diabetes Prevention Program)
- CDC: Are you eligible for the National DPP lifestyle change program?
- ADAG study (eAG formula)
Last reviewed: by the Diabetes Blogs editorial team. Information only, not medical advice.

