LabCorp accepts Medicare at most of its locations, but coverage and your out-of-pocket cost depend on which Medicare plan you have and whether your doctor orders the test as medically necessary.

LabCorp is one of the largest clinical laboratory networks in the United States, with thousands of patient service centers. Medicare Part B covers laboratory tests when a doctor orders them for diagnosis or treatment of a medical condition. LabCorp participates in Medicare nationwide, meaning it has agreed to accept Medicare as payment. However, "accepts Medicare" does not mean the test is free or that LabCorp will bill Medicare automatically — you need to understand what your specific plan covers and what paperwork your doctor must send.

The key issue is that LabCorp is a lab company, not a hospital or doctor's office. When your doctor orders a test, the test itself is covered by Medicare Part B if medically necessary. But LabCorp must receive the order from your doctor in the right format, and you must bring your Medicare card and any other insurance cards when you go to the lab. If LabCorp does not receive the order or bills you directly without trying Medicare first, you have the right to dispute the charge.

Key Takeaways

  • LabCorp participates in Medicare nationwide, which means it accepts Medicare as a form of payment for lab tests ordered by your doctor.
  • Your doctor must submit the lab order to LabCorp in writing or electronically; verbal requests or orders sent only to you may not reach the lab.
  • You pay a 20 percent coinsurance on most lab tests after you meet your Part B deductible, unless the test is one of the preventive screenings Medicare covers at no cost.
  • Bring your Medicare card and any secondary insurance cards to your LabCorp appointment so the lab can bill correctly.
  • If LabCorp bills you the full cost without submitting to Medicare first, you can file a complaint with Medicare and ask LabCorp to resubmit the claim.

How Medicare Part B covers lab tests at LabCorp

Medicare Part B is the part of Original Medicare that covers outpatient services, including laboratory and diagnostic tests. When your doctor orders a test at LabCorp and that test is medically necessary — meaning it is used to diagnose, treat, or monitor a condition — Medicare Part B will cover it. You are responsible for 20 percent of the Medicare-approved amount after you have paid your annual Part B deductible, which is $240 in 2024. Some preventive lab tests, such as certain cancer screenings and cholesterol checks, are covered at no cost to you.

The test must be ordered by a doctor, nurse practitioner, or other may have access to healthcare provider. LabCorp cannot perform a test just because you request it; the order must come from your medical provider. If you have a Medicare Advantage plan (Part C) instead of Original Medicare, your coverage and costs may differ. Medicare Advantage plans must cover at least what Original Medicare covers, but they may have different copays, coinsurance amounts, or network restrictions. Check your plan documents or call your plan's customer service number to confirm coverage before you go to LabCorp.

What you need to bring to your LabCorp appointment

Bring your Medicare card, a photo ID, and any other insurance cards you have. If you have a secondary insurance policy — such as Medicaid, a Medigap plan, or employer coverage — LabCorp will bill Medicare first and then submit to your secondary insurance. Do not assume LabCorp has your insurance information just because your doctor has it. Labs and doctor's offices use separate billing systems, so the order reaching your doctor does not mean LabCorp has your Medicare details.

Ask your doctor's office to confirm that they are sending the lab order directly to LabCorp, not just giving you a paper slip to carry. Paper requisitions can be lost or delayed. If your doctor's office uses electronic health records, they can send the order electronically, which is faster and more reliable. Before you leave your doctor's appointment, ask for the name of the specific LabCorp location where you should go, because LabCorp has many patient service centers and your doctor may have a preferred location.

When LabCorp might bill you directly instead of Medicare

LabCorp should always bill Medicare first if you are on Original Medicare and the test is medically necessary. However, mistakes happen. LabCorp might bill you directly if the lab did not receive your doctor's order, if your Medicare information was entered incorrectly, or if the test is not one that Medicare covers. Some tests that doctors order are not covered by Medicare — for example, certain genetic tests, wellness panels, or tests ordered for life insurance purposes. Before you go to the lab, ask your doctor whether the test is covered by Medicare.

If LabCorp sends you a bill for the full cost of the test, do not pay it when ready. Call LabCorp's billing department and ask whether they submitted the claim to Medicare. If they did not, ask them to submit it. If they say the test is not covered by Medicare, ask your doctor to confirm whether the test is medically necessary. You can also call Medicare at 1-800-MEDICARE to ask whether a specific test is covered. If LabCorp billed you and Medicare should have paid, you can file a complaint with Medicare and ask LabCorp to refund you once Medicare pays.

Understanding your out-of-pocket costs

Your cost for a LabCorp test depends on whether you have met your Part B deductible and whether the test is preventive. If you have not met your $240 annual deductible, you pay the full cost of the test until the deductible is satisfied. Once you have met the deductible, you pay 20 percent of the Medicare-approved amount. The Medicare-approved amount is not the same as LabCorp's list price — it is the amount Medicare has determined is reasonable for that test. LabCorp must accept the Medicare-approved amount as payment in full (except for your 20 percent coinsurance).

Some lab tests are covered at no cost under Medicare's preventive services benefit. These include certain cancer screenings, cardiovascular disease screenings, and diabetes screenings. A full list is available on Medicare.gov. If your doctor orders a test that is on the preventive list and codes it as preventive, you should not owe anything. However, if your doctor codes the same test as diagnostic (because you have symptoms), Medicare may charge you coinsurance. Ask your doctor's office which code they are using if you are unsure.

What to do if you have a Medicare Advantage plan

If you have a Medicare Advantage plan, LabCorp should still accept your plan because all Medicare Advantage plans must cover the same services that Original Medicare covers. However, your copay or coinsurance may be different, and some LabCorp locations may not be in your plan's network. Before you go to the lab, call your Medicare Advantage plan's customer service number and confirm that the specific LabCorp location you plan to visit is in-network. Out-of-network labs may charge you more.

Some Medicare Advantage plans require prior authorization before certain tests. This means your doctor must get approval from your plan before ordering the test. If your doctor does not get prior authorization and you go to LabCorp, you might be billed for the full cost. Ask your doctor's office whether your plan requires authorization for the test your doctor is ordering. If it does, make sure the office submits the authorization request before you schedule your LabCorp appointment.

How to resolve billing problems with LabCorp

If you receive a bill from LabCorp that you believe Medicare should have paid, start by calling LabCorp's patient billing department. Have your Medicare claim number (on your Medicare card) and the date of service ready. Ask LabCorp whether they submitted the claim to Medicare and, if so, what Medicare's response was. If LabCorp says they did not submit the claim, ask them to submit it when ready. If LabCorp says Medicare denied the claim, ask for a copy of the denial letter.

If LabCorp will not resubmit the claim or if you disagree with the denial, you can file an appeal with Medicare. Call 1-800-MEDICARE and ask how to appeal a claim denial. You can also file a complaint about LabCorp's billing practices with Medicare if you believe the lab is not following Medicare rules. Keep copies of all bills, explanation of benefits statements, and correspondence with LabCorp. These documents are important if you need to dispute a charge or file a complaint.

Frequently Asked Questions

Do I need to pay LabCorp upfront before the test?

LabCorp may ask you to pay your estimated coinsurance at the time of your visit, but they should not ask you to pay the full cost of the test. If they do, tell them you have Medicare and ask what your coinsurance amount is. If you have not met your deductible, you may owe the full deductible amount. Ask LabCorp for an estimate before the test if you want to know your cost in advance.

What if my doctor ordered the test but LabCorp says they did not receive the order?

Call your doctor's office and ask them to resend the order to LabCorp. Ask whether they sent it electronically or by fax, and get the fax number or contact information for the specific LabCorp location. If your doctor's office resends the order and LabCorp still says they did not receive it, ask your doctor to call LabCorp directly to confirm the order. Do not go to the lab until the order is confirmed.

Can I use LabCorp if I have both Medicare and Medicaid?

Yes. LabCorp accepts both Medicare and Medicaid. When you have both, Medicare is your primary insurance and Medicaid is secondary. Bring both cards to your appointment. LabCorp will bill Medicare first, and then bill Medicaid for any remaining balance. Your out-of-pocket cost depends on your Medicaid plan's rules.

Are home collection tests from LabCorp covered by Medicare?

LabCorp offers home collection kits for some tests. Medicare covers these tests the same way it covers tests done at a LabCorp patient service center — your doctor must order them and they must be medically necessary. However, not all tests are available as home collection kits. Ask your doctor whether the test you need can be done at home, and confirm with LabCorp that they will bill Medicare for a home collection test.

What if LabCorp is out of network for my Medicare Advantage plan?

If the LabCorp location is out of network, you may owe more than you would at an in-network lab. Call your Medicare Advantage plan before you go and ask what your out-of-network coinsurance is. If possible, ask your doctor to order the test at an in-network lab instead. If you must use an out-of-network LabCorp location, ask for an estimate of your cost before the test.