The A1C test, also known as the glycated hemoglobin or HbA1c test, is a simple blood measure that provides an estimate of your average blood sugar levels over the preceding two to three months. This test is a standard tool used by healthcare professionals for screening, diagnosing, and monitoring prediabetes and diabetes. Unlike a fingerstick glucose check, which offers a snapshot of your blood sugar at a single moment, the A1C test captures the percentage of hemoglobin protein in your red blood cells that has sugar attached to it. The higher your blood sugar has been over that period, the higher the resulting percentage will be.
Testing Through Healthcare Providers
The most accurate and reliable method for checking A1C is through a traditional healthcare setting, which involves a laboratory analysis of a venous blood sample. This typically begins with a visit to a primary care physician, who issues a formal lab order. The sample is then drawn from a vein in your arm at a dedicated clinical laboratory, such as Quest Diagnostics or LabCorp, or a hospital-based lab.
These clinical laboratories use standardized methods that are the gold standard for accuracy and are required for a formal diagnosis. Since a physician orders the test, the results are integrated directly into your official medical record, ensuring continuity of care. Insurance coverage is often robust for these diagnostic and monitoring tests.
The A1C test is convenient because it does not require the patient to fast beforehand, unlike some other glucose tests. Coverage has expanded for screening purposes, making it more accessible. For individuals with existing diabetes, the A1C test is routinely ordered at least twice a year to monitor treatment effectiveness.
Accessible Testing Options
For those seeking a quick, convenient check without a doctor’s visit, several accessible testing options are available, though they are primarily intended for screening or monitoring, not diagnosis. Many retail pharmacies and local health clinics offer point-of-care A1C screening, often utilizing a finger-prick blood sample. Results are typically available within minutes.
These point-of-care tests offer speed and convenience, but they may be less precise than the clinical laboratory gold standard. The cost for these screenings is usually an out-of-pocket fee, as they are often not covered by insurance. The quick result provides an immediate estimate, allowing you to gauge your average blood sugar and decide if follow-up is needed.
Another option is the direct-to-consumer at-home A1C test kit, which can be purchased online or at a drugstore. These kits require you to collect a small blood sample yourself via a fingerstick. You then either analyze it with a small device or mail the sample to a certified laboratory. While highly convenient, accuracy can be affected by user technique and proper handling.
Understanding the Results and Next Steps
The A1C result is expressed as a percentage, reflecting the fraction of hemoglobin coated with sugar. A result below 5.7% is considered within the normal range. Prediabetes is diagnosed when the A1C falls between 5.7% and 6.4%, signaling an elevated risk of developing type 2 diabetes and cardiovascular disease.
A result of 6.5% or higher on two separate occasions is the threshold for a diabetes diagnosis. If a screening test shows an elevated number, the immediate next step is to schedule an appointment with a healthcare provider for a confirmatory, laboratory-grade test. Only a physician can provide a formal diagnosis and discuss a treatment plan.
The frequency of testing depends on your health status. People with prediabetes are often recommended to retest every one to two years. For those with a diabetes diagnosis, testing is generally recommended every three to six months, particularly if treatment goals are not being met or medication has changed. The result provides actionable information that a doctor will use to discuss lifestyle changes or adjust existing medication.