Medicare does not cover routine blood work ordered simply as part of a general checkup, but it does cover diagnostic blood tests your doctor orders to investigate a symptom or manage a condition, along with a defined set of preventive screenings. For the blood tests Medicare does cover, most people pay nothing: clinical lab services paid under Medicare’s Clinical Laboratory Fee Schedule are exempt from the Part B deductible and the usual 20% coinsurance.1Centers for Medicare & Medicaid Services. Medicare Claims Processing Manual – Chapter 16 – Laboratory Services
Why Routine Blood Work Falls Outside Coverage
Medicare draws a hard line between tests ordered for a medical reason and tests ordered “just to check.” A comprehensive metabolic panel or complete blood count your doctor orders because you’re experiencing fatigue, unexplained weight loss, or another symptom is diagnostic and covered. The same panel ordered during an annual physical to see how things look is considered routine and generally falls outside Medicare’s coverage rules.2Medicare.gov. Diagnostic Laboratory Tests
Federal regulations require that every diagnostic lab test be ordered by the physician treating you for a specific medical problem, and that the doctor use the results to manage that problem. Tests that don’t meet this standard are classified as not reasonable and necessary, which is Medicare’s way of saying it won’t pay.3eCFR. 42 CFR Part 410 Subpart B – Medical and Other Health Services
The practical takeaway: if your doctor documents a clinical reason for the blood test, Medicare will typically cover it. Without a documented diagnosis, symptom, or risk factor, you could be responsible for the full bill.
Preventive Blood Screenings Medicare Does Cover
Medicare Part B carves out specific preventive blood tests you can get without symptoms, as long as you meet eligibility criteria and stay within frequency limits. These cost nothing when your provider accepts assignment.
- Cardiovascular disease screening. Blood tests for cholesterol, lipid, and triglyceride levels, covered once every five years.4Medicare.gov. Cardiovascular Disease Screenings
- Diabetes screening. Fasting or non-fasting blood glucose tests, covered up to twice per year if you’re at risk. Risk factors include high blood pressure, obesity, abnormal cholesterol, a history of high blood sugar, or a combination of age 65-plus with family history of diabetes or being overweight.5Medicare.gov. Diabetes Screenings
- Prostate cancer screening. A prostate-specific antigen (PSA) blood test covered once every 12 months for men who have reached age 50.6Centers for Medicare & Medicaid Services. NCD – Prostate Cancer Screening Tests (210.1)
- HIV screening. Covered annually for anyone between ages 15 and 65, or outside that range if you’re at increased risk. Pregnant women can receive up to three screenings during a pregnancy.7Medicare.gov. HIV (Human Immunodeficiency Virus) Screenings
- Hepatitis C screening. Covered once for people born between 1945 and 1965. If you’re at high risk due to injection drug use, coverage is annual as long as the risk continues.8Medicare.gov. Hepatitis C Virus Infection Screenings
- Hepatitis B screening. Covered yearly if you’re at high risk for HBV infection and haven’t been vaccinated, or at specific points during pregnancy.9Medicare.gov. Hepatitis B Virus (HBV) Infection Screenings
Ask for one of these more often than the frequency rules allow without a documented medical reason and the claim will likely be denied. The cardiovascular screening’s five-year interval catches people off guard the most.
What Counts as a Diagnostic Blood Test
Outside the preventive list, Medicare Part B covers clinical diagnostic blood tests when your treating physician orders them to diagnose, rule out, or monitor a medical condition. This is a broad category. Tests for organ function, blood cell counts, thyroid levels, infection markers, and disease-specific indicators all qualify as long as a documented medical reason supports the order.10Medicare.gov. Clinical Laboratory Tests
Two conditions matter. The doctor ordering the test must be the one treating you for the condition and must use the results in managing your care. A referral for labs from a physician who isn’t actively treating the condition may not be covered. The test also has to be performed at a Medicare-participating facility.3eCFR. 42 CFR Part 410 Subpart B – Medical and Other Health Services
The Annual Wellness Visit Isn’t a Physical
This is where the confusion usually starts. Medicare’s Annual Wellness Visit is covered once every 12 months at no cost, but it’s not a physical exam and does not include blood work as a standard component. The visit focuses on health risk assessments, reviewing your medical history, checking vitals like blood pressure and weight, and building a personalized prevention plan.11Medicare.gov. Yearly “Wellness” Visits
If your doctor identifies a concern during the wellness visit and orders blood tests as a result, those tests are billed separately as diagnostic services. They may be covered if they meet the medical necessity standard, but the visit’s free status doesn’t extend to whatever gets ordered alongside it.
The one-time “Welcome to Medicare” preventive visit, available within the first 12 months of Part B enrollment, works similarly. It includes a physical exam and a screening electrocardiogram, but not automatic blood panels.12Centers for Medicare & Medicaid Services. Initial Preventive Physical Exam
What Covered Blood Work Costs
Medicare’s lab coverage is genuinely generous compared to most other Part B services. Clinical diagnostic laboratory tests paid under the Clinical Laboratory Fee Schedule are exempt from both the annual Part B deductible and the 20% coinsurance. Medicare pays the lab directly, and the lab cannot bill you for any remaining balance.1Centers for Medicare & Medicaid Services. Medicare Claims Processing Manual – Chapter 16 – Laboratory Services
This applies whether the test is run at an independent laboratory, a hospital outpatient lab, or a critical access hospital. In practice, the vast majority of covered outpatient blood tests cost you $0. The preventive screenings above are also $0 when your provider accepts assignment.4Medicare.gov. Cardiovascular Disease Screenings
One thing to keep in mind: the doctor’s office visit where the blood draw is ordered carries its own cost-sharing. Even when the lab test itself is free, you’ll still owe coinsurance on the office visit unless it qualifies as a covered preventive service.
If Medicare Says No
If Medicare determines that a blood test wasn’t medically necessary, or didn’t meet the frequency rules for a preventive screening, it will deny the claim and you’ll owe the full cost. Your doctor’s office should warn you in advance by having you sign an Advance Beneficiary Notice of Non-coverage (ABN) before the test is performed.13Centers for Medicare & Medicaid Services. Form Instructions Advance Beneficiary Notice of Non-coverage (ABN)
The ABN gives you options: proceed with the test and have Medicare billed so you get an official coverage decision you can then appeal, or proceed and pay out of pocket without involving Medicare. If you weren’t given an ABN before an uncovered test, you may not be responsible for the charge. The ABN is the provider’s responsibility.
Common denial situations include cardiovascular screenings ordered less than five years after the last one, diabetes screenings without documented risk factors, and broad panels ordered without a specific diagnosis code. If your doctor believes the test is warranted, ask them to confirm the diagnosis code supports medical necessity before the lab processes the order.
You can appeal a denial. The first step is a redetermination, filed within 120 days of the initial claim decision using form CMS-20027 or a letter to the Medicare Administrative Contractor listed on your Medicare Summary Notice. The contractor generally issues a decision within 60 days.14Centers for Medicare & Medicaid Services. First Level of Appeal – Redetermination by a Medicare Contractor Appeals cost nothing to file and succeed more often than people expect when the doctor provides a letter explaining the medical rationale behind the order.
A Note for Medicare Advantage Enrollees
If you’re enrolled in a Medicare Advantage plan (Part C) rather than Original Medicare, your plan must cover at least everything Original Medicare covers, including diagnostic and preventive blood work. Advantage plans may require you to use in-network laboratories and can use copayments instead of the $0 lab coinsurance. Check your plan’s provider directory before scheduling lab work to avoid surprise out-of-network charges.15HHS.gov. What Is Medicare Part C?