Does Medicare Cover A1C Tests?

Executive Summary

Medicare Part B covers A1C tests at 100% cost (no co-pay) if you have a diagnosis of diabetes or if you are at high risk. For those with diabetes, Medicare typically covers the test once every 3 months. For those at risk but not yet diagnosed, Medicare covers the test up to twice per year as part of its screening program.

Medicare Coverage Categories

Medicare splits A1C coverage into two main categories: Screening (pre-diagnosis) and Management (post-diagnosis).

Condition	Medicare Frequency	Patient Cost
Diagnosed Diabetes	Every 3 months (4x per year)	$0 (100% Covered)
High Risk / Prediabetes	Every 6 months (2x per year)	$0 (100% Covered)
General Screening	Once per year	$0 (100% Covered)
Gestational Diabetes	As medically necessary	$0 (100% Covered)

1. Coverage for Diagnosed Patients

If you have already been diagnosed with Type 1 or Type 2 diabetes, Medicare recognizes the A1C test as a "medically necessary" monitoring tool. Your doctor must order the test, and it must be performed in a Medicare-certified laboratory. You typically pay $0 for this test.

2. Coverage for "At-Risk" Patients (Screening)

Medicare also covers A1C tests for people who do not have diabetes but have risk factors, such as:

High blood pressure (Hypertension).
History of abnormal cholesterol levels.
Overweight (Obesity).
History of high blood sugar.

Under the Medicare Diabetes Prevention Program, these screening tests are considered preventive services and are fully covered once or twice per year depending on the specific risk factors.

Clinical Guidance

To ensure your test is covered, your doctor must use the correct ICD-10 code (diagnosis code) on the lab order. If the code is for "Routine Wellness" rather than "Diabetes Screening," Medicare might deny the claim.

What is NOT Covered?

At-Home Kits: Medicare generally does not reimburse for over-the-counter A1C kits purchased at pharmacies like Walmart or Walgreens.
Excessive Testing: If you request an A1C test every month, Medicare will likely deny the extra tests unless your doctor provides a specific medical reason (such as a major medication change or pregnancy).

Medicare Advantage Plans (Part C)

If you have a private Medicare Advantage plan (like those from UnitedHealthcare, Humana, or Aetna), they are required to cover at least as much as original Medicare. Many of these plans offer additional benefits, such as free at-home testing supplies or rewards for keeping your A1C under 7.0%.

Convert Your Medicare Lab Results to Daily Glucose →

Frequently Asked Questions

Is the A1C test free with Medicare?

Yes. As long as your doctor orders it and you meet the eligibility criteria (risk factors or diagnosis), the A1C test is a "preventive service" or "medically necessary lab," meaning you pay nothing out-of-pocket.

Can I get an A1C test every month on Medicare?

Usually, no. Medicare’s standard limit is once every 90 days. If your doctor needs a test more frequently, they must provide a "Letter of Medical Necessity" to explain why the extra testing is required.

Does Medicare cover the GMI/CGM version of A1C?

Medicare Part B covers Continuous Glucose Monitors (CGM) for patients who take insulin or have a history of severe hypoglycemia. The GMI (Glucose Management Indicator) provided by these devices is accepted by Medicare doctors as a valid measure of glucose health.

The Biochemistry of Glycated Hemoglobin

To understand A1C, we must look at the Amadori rearrangement. This is a series of chemical reactions where glucose bonds to the N-terminal valine of the hemoglobin beta chain. Because this bond is nearly irreversible, the percentage of glycated hemoglobin remains stable throughout the 120-day lifespan of the erythrocyte. This makes A1C a superior metric for long-term glycemic control compared to transient plasma glucose tests.

References

Learn more in our comprehensive What is A1C? complete guide.