CPT 85025 is the billing code for a complete blood count (CBC) with an automated differential. It covers a standard blood test that measures five core components: hemoglobin, hematocrit, red blood cell count, white blood cell count, and platelet count, plus a machine-generated breakdown of the different types of white blood cells in your sample. This is one of the most commonly ordered lab tests in medicine, used for everything from routine checkups to monitoring chronic illness.
What the Test Measures
A CBC with automated differential gives your provider a snapshot of three major cell types circulating in your blood: red blood cells, white blood cells, and platelets. Each tells a different story about your health.
Red blood cells (RBCs) carry oxygen throughout your body. The test measures them in three ways: a direct count of red blood cells, hemoglobin (the oxygen-carrying protein inside those cells), and hematocrit (the percentage of your blood volume made up of red cells). Together, these values reveal whether you have anemia or, less commonly, too many red blood cells.
White blood cells (WBCs) are your immune system’s frontline. The total white blood cell count shows whether your body is fighting an infection, dealing with inflammation, or responding to a medication. The “automated differential” portion is what separates this code from a simpler CBC. It uses a machine to sort your white blood cells into subtypes, typically neutrophils, lymphocytes, monocytes, eosinophils, and basophils. Each subtype responds to different threats, so the breakdown helps narrow down what’s going on. Elevated eosinophils, for example, can point toward allergies or parasitic infections, while a spike in neutrophils often signals a bacterial infection.
Platelets are cell fragments that help your blood clot. A count that’s too low can mean increased bleeding risk, while a count that’s too high may raise concerns about clotting disorders.
Normal Reference Ranges
Reference ranges vary slightly between labs, but Cleveland Clinic lists these as typical adult values:
- White blood cells: 4,000 to 10,000 cells per microliter
- Red blood cells: 4.0 to 5.4 million cells per microliter for females (or those taking estrogen), 4.5 to 6.1 million for males (or those taking testosterone)
- Hemoglobin: 11.5 to 15.5 g/dL for females, 13 to 17 g/dL for males
- Hematocrit: 36% to 48% for females, 40% to 55% for males
- Platelets: 150,000 to 400,000 cells per microliter
A result outside these ranges doesn’t automatically mean something is wrong. Dehydration, recent exercise, altitude, pregnancy, and many medications can shift values temporarily. Your provider interprets results in the context of your symptoms and medical history.
How CPT 85025 Differs From 85027
The key distinction comes down to the differential. CPT 85025 includes the automated differential white blood cell breakdown. CPT 85027 covers the same CBC panel (hemoglobin, hematocrit, RBC, WBC, and platelets) but without sorting the white blood cells into subtypes. If a physician orders “a CBC” with no mention of a differential, the correct code is 85027. If the order specifies a differential, or the lab routinely runs one as part of the CBC, 85025 applies.
In practice, most modern hematology analyzers generate the differential automatically, which is why 85025 is far more commonly billed than 85027. Some payers and facilities default to 85025 for nearly all CBC orders.
Why This Test Gets Ordered
A CBC with automated differential is one of the broadest screening tools available. Providers order it for a wide range of reasons: annual wellness exams, pre-surgical evaluations, monitoring the effects of chemotherapy or other medications that affect blood cells, investigating unexplained fatigue or fever, tracking infections, and evaluating bleeding or bruising that seems unusual. It’s also a first-line test when blood cancers like leukemia or lymphoma are suspected, because these conditions produce characteristic changes in white blood cell counts and types.
Because the test covers so much ground, it often appears alongside other lab work. If your provider ordered additional tests on the same blood draw, you may need to fast beforehand. The CBC itself doesn’t require fasting, but the accompanying tests might. Your provider’s office will tell you if any preparation is needed.
What the Blood Draw Involves
The test requires a simple venous blood draw, typically from a vein in your arm. The sample goes into a tube containing an anticoagulant to keep it from clotting, then runs through an automated hematology analyzer at the lab. Results are usually available within a few hours to one business day, depending on the facility. The draw itself takes under a minute, and most people experience nothing more than a brief pinch.
Billing and Coverage
CPT 85025 is covered by Medicare and most private insurers when there’s a documented medical reason for ordering it. For Medicare specifically, coverage falls under the National Coverage Determination for blood counts (NCD 190.15), which ties reimbursement to the diagnosis codes submitted with the claim. If you see this code on a bill and weren’t expecting it, it likely means your provider ordered a CBC with differential as part of your lab panel. The cost without insurance typically ranges from $10 to $50 at most commercial labs, making it one of the least expensive blood tests available.