A1C 5.7 to 6.4

If your A1C came back somewhere between 5.7% and 6.4%, that result falls inside what’s called the prediabetes range. It means your average blood sugar has been running higher than typical, but not high enough to be diagnosed as type 2 diabetes. This guide explains what that range means, why two people with the same number can get different follow-up advice, and what to bring to your next conversation with a clinician.

What the Prediabetes A1C Range Actually Means

The A1C test doesn’t measure your blood sugar at a single moment. It measures how much sugar has attached to the hemoglobin in your red blood cells, which reflects your average blood sugar level over roughly the past three months, since red blood cells regenerate on about that cycle. The result is reported as a percentage.

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), the three categories are:

Below 5.7% is considered a normal A1C level.
5.7% to 6.4% falls in the prediabetes range.
6.5% or above, confirmed with a second measurement, is used to diagnose diabetes.

A prediabetes-range result isn’t a diagnosis of diabetes, and it isn’t nothing, either. NIDDK notes that within the 5.7%–6.4% range itself, a higher number generally reflects a higher risk of progressing to type 2 diabetes than a number closer to 5.7%. The Centers for Disease Control and Prevention (CDC) reports that more than 2 in 5 U.S. adults have prediabetes, and most don’t know it, since the condition usually causes no noticeable symptoms.

Why Risk and Follow-Up Look Different From Person to Person

Two people can both land at, say, 6.0%, and still get different next steps from their clinician. That’s not inconsistency — several individual factors change what the number means and how it should be acted on.

Other risk factors you carry. NIDDK lists age, overweight or obesity, a family history of diabetes, physical inactivity, a history of gestational diabetes, and conditions like polycystic ovary syndrome or sleep apnea as factors that raise the chance prediabetes progresses. A clinician weighs your A1C alongside these, not in isolation.
Conditions that can skew the A1C number itself. Both NIDDK and the CDC note that certain conditions can make an A1C result falsely high or falsely low, including anemia, kidney failure, liver disease, blood disorders such as sickle cell disease or thalassemia, recent blood loss or a blood transfusion, hemodialysis, and early or late pregnancy. The CDC also names certain medicines — including opioids and some HIV medications — as factors that can distort the reading itself, separately from medicines that affect blood sugar levels more generally. If you’re of African, Mediterranean, or Southeast Asian descent, or have family members with sickle cell trait or thalassemia, NIDDK notes you may carry a hemoglobin variant that can interfere with some A1C test methods — most people with a variant have no symptoms and don’t know they carry it.
How the test was drawn. A standard A1C test doesn’t require fasting and can be drawn any time of day from a vein, sent to a lab using an NGSP-certified method. NIDDK specifically advises that point-of-care A1C results — the kind run in-office rather than sent to a lab — should not be used to diagnose prediabetes or diabetes.
Whether the result has been confirmed. If you don’t have symptoms, NIDDK recommends a repeat test on a different day, using the A1C or another diabetes test, before treating a single result as settled.
Pregnancy timing. NIDDK notes the A1C test reflects averages from the past three months, so a result taken early in pregnancy may partly reflect glucose levels from before conception — one reason other tests are typically used to check for gestational diabetes later in pregnancy.

This is also why retesting intervals, and even who gets tested in the first place, differ by person rather than following one fixed rule. NIDDK indicates testing may be considered starting at age 35, or younger with overweight or obesity plus other risk factors, while a separate CDC page references age 45 as a general testing trigger. The two don’t line up exactly — which is itself a useful reminder that population guidance shifts and that your own starting point is a question for your clinician, not a number to self-apply. On retesting: NIDDK notes that people with risk factors who test below the prediabetes range are generally retested at least every three years, while people with a prediabetes-range result are typically tested for type 2 diabetes annually; the CDC similarly notes a prediabetes-range result is usually followed by a repeat A1C every one to two years. Your own interval is a conversation for your clinician, based on your full picture.

Other Numbers You May See for the Same Question

If you’ve compared notes with someone else, or seen different-looking numbers elsewhere, a few things explain that without either number being wrong:

A1C isn’t the only diagnostic test. NIDDK notes clinicians may also use the fasting plasma glucose (FPG) test — where a prediabetes-range result is 100 to 125 mg/dL — or, less commonly, the oral glucose tolerance test (OGTT), where prediabetes falls between 140 and 199 mg/dL. These use different units and different testing conditions (FPG and OGTT require at least eight hours of fasting beforehand; A1C does not), so they aren’t interchangeable with the A1C percentage.
Estimated average glucose (eAG). Some labs report an eAG figure alongside A1C, which converts the percentage into the same mg/dL units used by home glucose meters. It’s a different way of expressing the same three-month average, not a separate test.
A1C and blood glucose tests can occasionally disagree. NIDDK notes it’s possible for one test to suggest diabetes while another doesn’t, particularly in early-stage changes. When that happens, clinicians typically repeat testing over the following months rather than relying on one result.

A Result-Context Worksheet for Your Next Conversation

Rather than trying to interpret the number yourself, it helps to arrive at your next visit — or phone call — with the full context gathered in one place. Consider noting:

Your exact result. The precise percentage, not a rounded memory of it.
When and how it was drawn. The date, and whether it was a standard lab draw from a vein or an in-office point-of-care test.
Whether it’s been repeated. If you’ve had more than one A1C or related test recently, note each date and result so a trend is visible, not just the latest number.
Current medicines and supplements. As noted above, some medicines can affect either blood sugar itself or the accuracy of the A1C reading — your clinician needs the full list either way.
Any symptoms, even mild or uncertain ones. Most people with prediabetes have no symptoms, so noting “none” is itself useful information — but mention anything that’s felt different, however minor it seems.
The one question you most want answered. For many readers it’s some version of: “Given my result and my risk factors, what would you recommend I do next, and when should I be retested?” Writing your question down before the visit makes it easier to ask directly and get a direct answer.

This worksheet is meant to organize what you bring to a clinician — not to help you interpret the result on your own or decide what to do about it without them.

When to Seek Care Right Away

If a clinician has told you a result needs urgent follow-up, or you’re experiencing symptoms that feel severe or are getting worse, don’t wait to sort out the testing details first — contact your clinician’s office or seek care promptly. If you think you’re having a medical emergency, call your local emergency number right away.

What This Article Covers — and What It Doesn’t

This guide is meant to help you understand what a prediabetes-range A1C result means in general, and why follow-up isn’t one-size-fits-all. It does not diagnose your condition, tell you whether treatment is needed, or replace a conversation with your clinician about your specific health history. Only a clinician with your full medical picture can tell you what your result means for you and what should happen next.

If you’re working through a single result flagged outside its reference range more generally, rather than a specific A1C question, see An Out-of-Range Lab Flag: Questions About Reference Ranges at Primary Care. If your A1C changed from a past result and you’re trying to compare the two numbers directly, see A Lab Result Changed: How to Compare Dates, Units, and Reference Ranges.

This article is for general educational purposes and isn’t a substitute for professional medical advice, diagnosis, or treatment. Always talk with a qualified healthcare provider about your own test results and health needs.

Sources: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), “What Is Diabetes?,” “Insulin Resistance & Prediabetes,” and “The A1C Test & Diabetes”; Centers for Disease Control and Prevention (CDC), “Diabetes Basics” and “A1C Test for Diabetes and Prediabetes.”

By Primary Care Visit Guide Editorial Team.