Short answer up top, then the exact rule. Here's what Original Medicare does and doesn't cover for blood tests in 2026 — and where a Medicare Advantage plan can fill the gap.
Quick answer: Yes. Part B covers medically necessary diagnostic laboratory tests — blood tests, urinalysis, and certain tissue tests — when your provider orders them. This is one of the few benefits where you usually pay nothing: no 20% coinsurance and no deductible, as long as the lab is Medicare-accredited.
Medicare Advantage (Part C) plans must cover the same diagnostic lab tests as Original Medicare, but they run them through a network — using an out-of-network lab is the most common way people get a surprise bill for routine blood work. Some plans also apply a copay. Confirm the lab is in your plan's network before your blood draw.
Anyone on Medicare with routine or ongoing lab work — annual panels, cholesterol checks, diabetes monitoring. Because covered lab tests are typically $0, the thing to watch isn't the cost-share, it's whether the lab is accredited (Original Medicare) or in network (Advantage).
See the current Part A, Part B, and Part D numbers — premiums, deductibles, and the new drug cap — in one place. Free, no signup.
See 2026 Medicare Costs →You usually pay nothing for Medicare-covered diagnostic laboratory tests — the Part B deductible and the usual 20% coinsurance generally don't apply. The test must be medically necessary, ordered by your provider, and done by a Medicare-accredited provider. On a Medicare Advantage plan you pay the plan's cost-sharing and need to use an in-network lab.
Medicare covers lab tests that are medically necessary and ordered by a provider to diagnose or treat a condition, plus certain preventive screenings on a set schedule. Blood work with no medical reason behind it, or repeated more often than Medicare allows, may not be covered — ask your provider why a test is being ordered if you're unsure.
Coverage gaps in Original Medicare — like blood tests — are exactly what a Medicare Advantage or Medigap plan is meant to fill. Our free Enrollment Finder shows the window you can switch in, and the guide library walks through the trade-offs. This page is free to share with anyone weighing their options.
Open the Enrollment Finder →This answer is based on U.S. government Medicare coverage rules: