Medicare covers most blood tests your doctor orders, but you pay a share of the cost depending on whether the test happens in a hospital, a lab, or your doctor's office.

Medicare Part B covers lab work and blood tests when a doctor orders them for diagnosis or treatment. You typically pay 20% of the cost after you meet your Part B deductible (which is $240 in 2024, though this amount changes yearly). The lab or facility bills Medicare first, then sends you a bill for your share.

The catch is that coverage depends on three things: whether your doctor orders the test, whether the lab is in Medicare's network, and what the test is for. A blood test to check your cholesterol because you have heart disease is covered. A blood test you order yourself online without a doctor's order is not.

Key Takeaways

  • Medicare Part B covers blood tests when your doctor orders them for a medical reason, and you pay 20% of the approved cost after your deductible.
  • Tests done at hospital outpatient labs, independent labs, and doctor's offices are all covered, but the facility must be in Medicare's network.
  • Preventive blood tests like cholesterol screening and diabetes screening are covered at no cost to you if done at an in-network facility.
  • Tests you order yourself without a doctor's order, or tests done at non-network labs, are your responsibility to pay for in full.
  • If you have a Medigap or Medicare Advantage plan, your out-of-pocket cost may be lower than the standard 20% coinsurance.

Which Blood Tests Are Covered at No Cost

Medicare covers certain preventive blood tests with no coinsurance or copay if the test is done at an in-network facility. These include cholesterol screening (lipid panel), diabetes screening (fasting glucose or A1C), and colorectal cancer screening blood tests. Your doctor must order the test as part of a preventive visit, not as part of treatment for an existing condition.

The difference matters. If your doctor orders a cholesterol test during your annual wellness visit to check your baseline, it is covered at no cost. If your doctor orders a cholesterol test three months later because you started a new medication and need to check how it is working, you pay 20% coinsurance. Both are legitimate medical reasons, but only the first is classified as preventive.

Blood Tests You Pay Coinsurance For

Any blood test ordered to diagnose or treat a condition — not to prevent one — falls under Part B's standard coinsurance rule. You pay 20% of Medicare's approved amount after your deductible. This includes tests for thyroid function, liver enzymes, kidney function, blood sugar monitoring, anemia, infection, or medication levels.

The approved amount is not always what the lab charges. Medicare sets a fee schedule for each test code. If the lab charges $200 but Medicare's approved amount is $100, you pay 20% of $100 ($20), not 20% of $200. The lab must write off the difference. This is why using an in-network lab matters — they have agreed to accept Medicare's approved amount.

Where the Test Happens Affects Your Cost

Blood tests are covered in three settings: your doctor's office, an independent lab, or a hospital outpatient lab. All three are covered by Medicare Part B if the facility is in-network and your doctor orders the test. Your coinsurance is the same (20% after deductible) regardless of location.

Hospital outpatient labs sometimes charge a facility fee on top of the lab fee. This means your 20% coinsurance may be higher than it would be at an independent lab for the same test. Before the test, ask whether the lab is hospital-based and whether there is a separate facility charge. If cost is a concern, ask your doctor whether the test can be done at an independent lab instead.

Tests You Order Yourself Are Not Covered

Direct-to-consumer blood tests — tests you order online or at a pharmacy without a doctor's order — are not covered by Medicare. Companies like EverlyWell, LetsGetChecked, and others advertise these tests directly to consumers. If you pay for one out of pocket, Medicare will not reimburse you, even if you later show the results to your doctor.

If you want a blood test covered, your doctor must order it. You do not need a referral or special permission. Call your doctor's office, describe your symptoms or concern, and ask whether a blood test makes sense. If your doctor agrees, they will send the order to a lab, and Medicare will cover its share.

Out-of-Network Labs and What You Owe

If your doctor orders a test at a lab that is not in Medicare's network, you may owe more than 20%. Out-of-network labs can charge whatever they want, and Medicare will only pay its approved amount. You are responsible for any difference between what the lab charges and what Medicare pays.

Before your test, ask your doctor's office which lab they are sending your blood to. Then call that lab or check Medicare's lab directory online to confirm it is in-network. If it is not, ask your doctor to send the order to an in-network lab instead. Most areas have multiple labs available, and your doctor can usually reroute the order with a quick phone call.

If You Have a Medigap or Medicare Advantage Plan

Your actual out-of-pocket cost depends on what other coverage you have. If you have a Medigap (supplemental) plan, it may cover some or all of your 20% coinsurance. If you have a Medicare Advantage plan, you pay whatever copay or coinsurance your plan sets for lab work — this is often lower than 20%, but varies by plan.

Check your plan documents or call your plan's customer service before your test to find out exactly what you will owe. This is especially important if the test is at a hospital outpatient lab, where facility fees can add up. Your plan may cover the lab fee but not the facility fee, or vice versa.

Frequently Asked Questions

Do I have to pay my deductible before blood tests are covered?

Yes, for diagnostic blood tests. You pay your full Part B deductible ($240 in 2024) before Medicare starts paying its share. Preventive blood tests are covered at no cost and do not count toward your deductible. Once you have met your deductible for the year, you pay only 20% coinsurance for the rest of the year.

What if my doctor orders multiple blood tests at the same time?

Each test is billed separately, and you pay 20% coinsurance for each one (after your deductible). If your doctor orders five different tests, you will receive one bill that lists all five, with your 20% share calculated for each. The total can add up, so ask your doctor whether all the tests are necessary or whether some can wait.

Can I get a blood test at an urgent care or emergency room?

Yes, and Medicare covers it the same way — you pay 20% coinsurance after your deductible. However, if the urgent care or ER is not in-network, you may owe more. Also, the facility may charge an urgent care or ER visit fee in addition to the lab fee. Call ahead to confirm the facility is in-network if possible.

What happens if I do not meet my deductible before the year ends?

Any blood tests you had that year count toward your deductible, but you pay the full cost out of pocket until you reach $240. Once you hit the deductible, Medicare starts paying its share (you pay 20%) for the rest of the year. Your deductible resets on January 1.

Are home blood draw services covered by Medicare?

Yes, if your doctor orders the test and the service is in-network. Some labs and phlebotomy services will come to your home to draw blood. Medicare covers this the same way it covers lab-based tests — you pay 20% coinsurance after your deductible. Confirm the service is in-network before scheduling.