Does Medicare Cover Diagnostic Lab Tests?

Medicare Part B covers lab tests used to diagnose or rule out a suspected illness or condition if the tests are medically necessary and a doctor orders them. Referred to as clinical diagnostic laboratory services, these tests are usually free for Medicare Part B beneficiaries.

Christian Simmons, writer and researcher for RetireGuide
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    Christian Simmons is a writer for RetireGuide and a member of the Association for Financial Counseling & Planning Education (AFCPE®). He covers Medicare and important retirement topics. Christian is a former winner of a Florida Society of News Editors journalism contest and has written professionally since 2016.

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  • Published: June 7, 2021
  • Updated: June 5, 2023
  • 5 min read time
  • This page features 14 Cited Research Articles
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Diagnostic Lab Test Coverage at a Glance

Medicare PlanDiagnostic Lab Test Coverage
Part A (Inpatient)Covered if medically necessary and ordered as part of an inpatient stay. Part A deductible applies.
Part B (Outpatient) Generally covered for approved tests.
Part C (Medicare Advantage)Covers everything covered by Medicare Part A and Part B. Select plans may provide additional benefits.
Part D (Prescription Drugs)N/A
Supplemental InsuranceCan help cover out-of-pocket testing costs. Coverage varies by plan.

What Clinical Diagnostic Laboratory Services Does Medicare Cover?

Medicare Part B covers several different types of diagnostic laboratory services, including blood tests and urinalyses.

Doctors use diagnostic laboratory services to identify the underlying illness or condition that’s causing a patient’s symptoms. Diagnostic tests are different from preventive tests, which proactively screen for illnesses in healthy patients and are often performed as part of routine checkups.

A newer type of test covered under Medicare Part B is an advanced diagnostic laboratory test, which evaluates your DNA, RNA or proteins to provide information about your health that no other test can produce.

According to the Centers for Disease Control and Prevention, genetic and genomic tests can be used to detect various illnesses, including cancer or other conditions that might run in your family.

Common Clinical Diagnostic Laboratory Services That Medicare Covers
Blood Test:
A very common test that uses your blood to evaluate your organs and test for various diseases and conditions.
A test that uses your urine to diagnose urinary tract infections, kidney issues and diabetes
Tests on Tissue Specimens:
Tests that are performed on removed tissue cells to identify conditions like cancer or cell damage
Tests on Other Bodily Fluids:
A wide-ranging group of tests that examine fluids other than blood or urine to identify or monitor diseases and conditions

Each of these tests is used to detect and diagnose a variety of diseases or disorders.

Blood Tests

Blood tests are one of many services Medicare covers. Your health care provider may order a blood test to check your organs for diseases and conditions such as anemia or cancer.

Blood tests are very common and are often done as part of regular checkups, but they are also used to diagnose suspected conditions. Different types of blood tests can identify different conditions.

According to the National Heart, Lung, and Blood Institute, one of the most common types is a complete blood count test, which measures the different parts of your blood to diagnose disorders like anemia or an infection.

A blood chemistry test, or basic metabolic panel, usually tests the chemicals in your plasma. This is used to check on your bones, muscles and organs and is often used to evaluate kidney function.

Another common type of blood test is a blood enzyme test, which records your troponin and creatine kinase levels to check if you have had a heart attack. There are also blood clotting tests, which can help determine if you are at risk for or have developed blood clots, which can be a very dangerous condition.


A urinalysis analyzes your urine to identify potential issues or diseases. According to the U.S. National Library of Medicine, this can be as simple as observing the color and odor of the urine sample or as complex as testing its acidity. This test also checks for blood, bacteria or anything else that should not be in the sample.

Urinalyses can diagnose UTIs, diabetes and potential kidney problems. They can also be used to continuously monitor health conditions and the effectiveness of treatments. As with other diagnostic lab tests, a urinalysis must be medically necessary and ordered by your doctor for Medicare to cover it.


Biopsies are used to diagnose dangerous or cancerous cells, and a sample can be taken from anywhere on the body.

According to the University of Illinois at Chicago College of Medicine, a biopsy is typically examined by a pathologist, who is trained specifically to examine tissue samples and diagnose possible conditions.

There are many types of biopsies, and samples are often taken with a needle. There are some types that do require surgery, such as when the sample is taken from inside your body.

While Medicare Part B covers medically necessary services and cancer-related treatments, there may be additional costs if you need surgery for a biopsy.

Medicare coverage of a biopsy surgery depends on your status as an inpatient or outpatient and whether you will require prescription drugs for your recovery. If you need drugs after your biopsy surgery, they would be covered under an optional benefit plan.

Be sure to check with your health care provider about any additional costs associated with a biopsy surgery and what will be covered.

Biopsies are not the only type of test done on tissue specimens, and others can be covered by Medicare.

Other Bodily Fluid Tests

There are other types of bodily fluids that might be collected and tested if you are suspected of having certain diseases. A pleural fluid test could be used to look for cancer, bacteria, inflammation or other possible conditions if you have pleural effusion, which occurs when fluid collects between the lining of the lungs and the chest wall.

Peritoneal fluid, which collects around internal organs in the abdomen, can also be tested for bacteria or other infections. Cerebrospinal fluid, which is the colorless liquid found in your brain and spinal cord, can be collected for tests to diagnose issues like meningitis or multiple sclerosis. And a pericardial fluid analysis can help diagnose the cause of inflammation or fluid around the heart.

Last Modified: June 5, 2023

14 Cited Research Articles

  1. Centers for Disease Control and Prevention. (2022, June 4). Genetic Testing. Retrieved from
  2. U.S. National Library of Medicine. (2021, May 4). Peritoneal Fluid Analysis. Retrieved from
  3. U.S. National Library of Medicine. (2021, May 4). Pleural Fluid Analysis. Retrieved from
  4. U.S. National Library of Medicine. (2021, April 12). Biopsy. Retrieved from
  5. U.S. Centers for Medicare & Medicaid Services. (2021, January). Provider Compliance Tips for Lab Tests — Urinalysis. Retrieved from
  6. U.S. National Library of Medicine. (2020, November 30). Cerebrospinal Fluid (CSF) Analysis. Retrieved from
  7. U.S. National Library of Medicine. (2020, September 22). What are the Types of Genetic Tests? Retrieved from
  8. U.S. National Library of Medicine. (2020, June 9). Urinalysis. Retrieved from
  9. Department of Health and Human Services. (2016, September). Changing How Medicare Pays for Clinical Diagnostic Laboratory Tests: An Update on CMS’s Progress. Retrieved from
  10. National Heart, Lung, and Blood Institute. (n.d.). Blood Tests. Retrieved from
  11. University of Illinois at Chicago Department of Pathology. (n.d.). Understanding Your Pathology Report. Retrieved from
  12. U.S. Centers for Medicare & Medicaid Services. (n.d.). Application for Advanced Diagnostic Laboratory Test (ADLT) Status Under the Medicare Clinical Laboratory Fee Schedule (CLFS). Retrieved from
  13. U.S. Centers for Medicare & Medicaid Services. (n.d.). Clinical Laboratory Tests. Retrieved from
  14. U.S. Centers for Medicare & Medicaid Services. (n.d.). Diagnostic Laboratory Tests. Retrieved from