What Is a Hemoglobin A1c Test? What It Measures and Costs

This page explains what the test measures and where to buy it. It does not explain what your number means: labs print their own reference ranges, and reading a result is a clinician's job. For every service ranked, see the best blood tests page; for which plans include A1c and what it costs on its own, see our HbA1c page.

What it measures

A1c is a single number, but the idea behind it takes a few steps. Hemoglobin is the protein in red blood cells that carries oxygen. Sugar in your blood attaches to it, and the more sugar there is, the more hemoglobin ends up coated.

MedlinePlus explains the time window in two lines: "Glucose sticks to hemoglobin for as long as the red blood cells are alive" and "Red blood cells live about three months" (MedlinePlus). Labcorp's own test page puts the window at "typically 8-12 weeks" (Labcorp OnDemand).

The National Institute of Diabetes and Digestive and Kidney Diseases says "The A1C test result is reported as a percentage" and that "The higher the percentage, the higher your blood glucose levels have been" (NIDDK). The same test goes by several names: NIDDK lists "hemoglobin A1C, HbA1c, glycated hemoglobin, or glycohemoglobin" (NIDDK), so a lab report or a membership's marker list may use any of them.

What can skew an A1c result

Because A1c depends on red blood cells, anything that changes them can change the number. MedlinePlus notes that "if you have a condition that affects your red blood cells, such as anemia or another type of blood disorder, an A1C test may not be accurate" (MedlinePlus), and that "Kidney failure and liver disease can also affect A1C results" (MedlinePlus). It also says "Certain medicines such as opioids and some HIV medicines may affect your results" (MedlinePlus) and asks you to tell your provider if you are pregnant. A CBC in the same order shows your red cell counts alongside the A1c, which gives a clinician more to read it against.

A1c versus a glucose test

A fasting glucose test, which is part of a CMP, measures the sugar in your blood at the moment of the draw. A1c averages over months. Labcorp's FAQ puts it this way: blood glucose shows "the amount of sugar in your blood at a given time" (Labcorp OnDemand). Many panels include both.

Where to get it and what it costs

Lab-test stores sell A1c on its own, with a physician order included, and send you to a Quest or Labcorp patient center for the draw. Some at-home brands, such as Everlywell and myLAB Box, also sell a mail-in kit. The table lists each seller's price, cheapest first, the fee it adds per order, and the memberships and panels that include A1c:

List prices from each store's own page. Memberships and panels that include it: Function Health, Superpower, Empirical Health, InsideTracker, Mito Health, Lifeforce, Marek Health, Labs by Hims, Maximus, Everlywell, Quest, Labcorp OnDemand, Ulta Lab Tests, SiPhox Health, LetsGetChecked.

Three things decide what you actually pay:

• The per-order fee can cost more than the test. On list price, Mito Health and Marek Diagnostics are the lowest, but both add a lab draw fee. Put every test you want in one order so you pay that fee once.
• A kit costs more than a draw. The at-home kits in the table cost several times what the cheapest lab stores charge, fee included. They save you a trip, not money.
• Your state decides whether you can buy at all. Lab-test stores do not sell in New York, New Jersey or Rhode Island; our guide to ordering your own blood test explains the rules.

A1c is in almost every broad membership. Function Health costs $365 a year and measures 99 markers; Superpower costs $199. One-time panels such as Ulta's Baseline panels include it too. Our lab order price page ranks one-time panels by cost per measured marker, and our guide to blood test cost without insurance prices A1c next to six other common tests.

Already have your results?

LifeFrom, a sister app from the team behind this site, can keep your results in one place and explain them in plain language (LifeFrom). It is our own product, so weigh that when you read this. For what a specific number means for you, ask the clinician who ordered the test or your own doctor.