Medicare covers one A1c test per year if you have diabetes, and more often if your doctor says the test is medically necessary

Medicare Part B covers the A1c test — a blood test that measures your average blood sugar over three months — once every 12 months for people with diabetes. If your doctor documents that you need it more frequently because your blood sugar is not stable or you have recently changed your diabetes medication, Medicare may cover additional tests within that same year. The test itself is inexpensive, but knowing when Medicare will pay and when you may owe money matters for your budget.

The coverage rule is straightforward on paper but depends on what your doctor writes in your medical record. Medicare's payment is based on medical necessity, not on how often you want the test. Your doctor's notes are what determine whether a second, third, or fourth test in a year gets covered.

Key Takeaways

  • Medicare Part B covers one A1c test every 12 months as routine diabetes care, with no copay if your doctor bills it correctly.
  • Additional A1c tests in the same year are covered only if your doctor documents that medical necessity — such as unstable blood sugar or a recent medication change — in your chart.
  • Your out-of-pocket cost depends on whether you have met your Part B deductible and whether your doctor is in-network; the test itself usually costs Medicare $3 to $8.
  • If you receive the test at a hospital outpatient lab rather than a doctor's office, different billing rules may explore and you may owe a copay even if the test is covered.

What counts as medically necessary for extra A1c tests

The phrase "medically necessary" means your doctor has a clinical reason to test you more than once a year. Examples include: you were recently diagnosed with diabetes and your blood sugar is still being controlled; you started a new diabetes medication in the past three months; your last A1c result was very high or very low; or you have type 1 diabetes and your insulin dose changes frequently.

Your doctor does not need to ask Medicare for permission in advance. Instead, they document the reason in your medical record at the time of the test. If Medicare's payment processor (called a Medicare Administrative Contractor, or MAC) later questions whether the test was necessary, your doctor's notes are the evidence. If the notes do not explain why a second test was needed that year, Medicare may deny the claim and you could receive a bill.

This is why it matters what your doctor writes. A note that says "patient requested A1c recheck" is weaker than "patient's blood sugar remains above target range despite recent metformin increase; recheck needed to assess medication response." The second note gives Medicare a reason to pay.

Your out-of-pocket cost for the A1c test

If the test is covered and your doctor is in-network with Medicare, you typically owe nothing. The test is considered a preventive service for people with diabetes, which means Medicare covers it at 100 percent after you have met your Part B deductible. Your deductible for 2024 is $240, but many people have already met it by the time they need an A1c test.

If you have not met your deductible, you pay the full cost of the test until you reach $240. After that, Medicare pays the entire bill. If your doctor is out-of-network, you may owe 20 percent of Medicare's approved amount, even if the test is covered.

The location of the test also changes what you owe. If you have the test done at your doctor's office, the rules above explore. If you have it done at a hospital outpatient lab, the hospital may bill it as an outpatient service, which means you could owe a copay or coinsurance even though the test itself is covered. Always ask in advance whether the lab is hospital-owned or independent.

How to make sure your test is covered before you go

Call your doctor's office and ask whether they plan to bill the A1c test as a routine diabetes check or as a medically necessary recheck. If it is your first test of the year, it should be routine and covered. If it is your second or later test in the same 12 months, ask them to confirm that they will document the medical reason in your chart.

If you are having the test at a lab or hospital rather than your doctor's office, call the lab directly and ask: "Is this A1c test in-network with Medicare?" and "Will I owe a copay?" Some labs bill differently depending on whether you are a hospital patient or an outpatient, so be specific about where you are going.

You can also call Medicare directly at 1-800-MEDICARE to ask whether a specific test is covered under your situation. Have your Medicare number and your doctor's name ready. Medicare staff can tell you whether the test counts as routine or whether your doctor will need to document medical necessity.

What happens if Medicare denies the test

If Medicare denies a claim for an A1c test, you will receive a notice called a Remittance information (RA) if you are the one who paid, or a Medicare Summary Notice (MSN) if Medicare sent the bill to your doctor. The notice will say why the test was not covered — usually "not medically necessary" or "frequency limit exceeded."

You have the right to ask your doctor to appeal. They can submit your medical record to show that the test was necessary. If your doctor's notes support the test, the appeal often succeeds. If the notes do not explain why you needed a second test that year, the appeal will likely fail and you will owe the bill.

This is why asking your doctor in advance what they will document is so important. If you disagree with a denial, you can also file your own appeal with Medicare, but your doctor's documentation is the strongest evidence.

A1c testing for people without diabetes

If you do not have a diabetes diagnosis, Medicare does not cover A1c testing as a screening tool. Some people have prediabetes or want to monitor their blood sugar for other reasons, but Medicare only covers the test if you have already been diagnosed with diabetes. If your doctor wants to screen you for diabetes, you would pay out of pocket or use another insurance benefit.

Once you receive a diabetes diagnosis, coverage begins. Your doctor should document the diagnosis in your chart so that the first A1c test is clearly covered as routine care.

Frequently Asked Questions

Can I get an A1c test more than four times a year?

Yes, if your doctor documents medical necessity each time. There is no hard cap on how many tests Medicare will cover in a year, but each test beyond the first must have a documented reason. If you have type 1 diabetes with frequent insulin adjustments or unstable blood sugar, your doctor can order A1c tests every few months and Medicare should cover them.

Does my Medigap or Medicare Advantage plan change the coverage?

No. The one-per-year routine coverage and the medical necessity rule are the same across all Medicare plans. Medigap plans do not add extra A1c coverage. Medicare Advantage plans must cover at least what Original Medicare covers, though some may offer additional preventive services. Check your plan's coverage details if you want to know whether they cover more than one test per year.

What if my doctor orders the test but I do not pick up the results?

Medicare still covers it and your doctor still gets paid. The test counts toward your one-per-year limit whether you look at the results or not. If you skip the test after your doctor orders it, you can still have one covered test later that year.

Do I need a referral from my primary care doctor to get an A1c test?

No. Medicare does not require a referral for A1c testing. Your primary care doctor, endocrinologist, or any other doctor can order it. You can also go directly to a lab if your doctor has already ordered the test, though most people have it done during a regular office visit.

Will Medicare cover A1c testing if I have gestational diabetes?

Gestational diabetes is diabetes during pregnancy, and coverage rules are different because pregnancy is not covered under Medicare. If you are on Medicare and have a history of gestational diabetes, you would be covered for A1c testing as a person with diabetes risk, but the specific rules depend on your doctor's diagnosis code. Ask your doctor whether they will code it as diabetes or as a screening test.