Complete Blood Count (CBC) with differential is one of the most commonly ordered laboratory tests to evaluate overall health and detect a wide range of disorders, including infections, anemia, and leukemia. This guide provides an in-depth look at the CPT codes for CBC with differential, including their applications, documentation requirements, and billing guidelines.
Overview of Complete Blood Count (CBC) with Differential
CBC with differential provides a detailed analysis of the different types of white blood cells (WBCs), red blood cells (RBCs), and platelets in a patient’s blood. This test helps healthcare providers assess:
- White blood cell count and differential
- Red blood cell count and indices
- Hemoglobin and hematocrit levels
- Platelet count and mean platelet volume
Key Components of CBC with Differential
- WBC Count and Differential – Measures total WBC count and categorizes types such as neutrophils, lymphocytes, monocytes, eosinophils, and basophils.
- RBC Count and Indices – Includes parameters such as mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and red cell distribution width (RDW).
- Hemoglobin and Hematocrit – Evaluates oxygen-carrying capacity.
- Platelet Count – Assesses clotting function.
CPT Codes for CBC with Differential
The following CPT codes are used to report CBC tests with differential, as well as related services that may be ordered alongside them.
Primary CBC Codes
- CPT 85025: Complete Blood Count (CBC) with automated differential white blood cell count.
- Lay Term: This code represents a fully automated analysis that provides a breakdown of the five major types of WBCs.
- Common Uses: Routine health checkups, monitoring conditions such as anemia, infection, and leukemia.
- Billing Tip: Ensure the test is medically necessary and linked to an appropriate diagnosis code.
- CPT 85027: Complete Blood Count (CBC), automated, without differential white blood cell count.
- Lay Term: A basic automated CBC without categorization of different WBC types.
- Common Uses: Used when a differential is not required, such as general screening.
- Billing Tip: Always specify whether differential analysis is needed to avoid coding errors.
- CPT 85004: Blood count; automated differential white blood cell count only.
- Lay Term: Reports the breakdown of WBCs without other CBC components.
- Common Uses: When only WBC analysis is needed for specific conditions.
- Billing Tip: Pair with CPT 85027 if a complete CBC is required.
Additional CBC-Related Codes
- CPT 85007: Blood smear, manual differential WBC count.
- Lay Term: A manual review of WBCs under a microscope by a laboratory technician.
- Common Uses: Confirming abnormal results from automated counts.
- Billing Tip: Use when automated testing produces inconclusive results.
- CPT 85008: Blood smear, manual RBC count, and morphology.
- Lay Term: Manual examination of red blood cells for shape and size abnormalities.
- Common Uses: Diagnosis of blood disorders such as sickle cell anemia.
- Billing Tip: Ensure documentation supports the need for manual review.
- CPT 85009: Blood smear, manual platelet estimate.
- Lay Term: Estimation of platelet count via manual review.
- Common Uses: Evaluating suspected clotting disorders.
- Billing Tip: Justify manual review with clinical indications.
Modifiers and Billing Guidelines
Modifiers
- Modifier 91: Repeat clinical diagnostic laboratory test.
- Use when the test is repeated for the same condition on the same day.
- Modifier QW: CLIA-waived test.
- Used when performing a waived test under CLIA regulations.
Documentation Requirements
- Clearly state the medical necessity for the test.
- Include physician’s order, lab results, and diagnostic codes.
- Differentiate between automated and manual procedures.
Common Billing Errors
- Reporting a CBC with differential (CPT 85025) when only a CBC without differential (CPT 85027) was performed.
- Failing to append modifier 91 for repeat tests.
- Submitting incomplete documentation leading to claim denials.
Practical Scenarios and Coding Examples
Scenario 1: Routine Health Screening
- Patient: A 45-year-old undergoing an annual checkup.
- Codes: CPT 85025 (CBC with automated differential).
- Notes: Ensure inclusion of medical necessity such as screening for anemia.
Scenario 2: Follow-up for Anemia
- Patient: A 32-year-old with a history of iron-deficiency anemia.
- Codes: CPT 85027 (CBC without differential) + CPT 85009 (manual platelet estimate).
- Notes: Documentation must support the necessity of manual platelet review.
Scenario 3: Infection Monitoring
- Patient: A 55-year-old being monitored for infection recovery.
- Codes: CPT 85025 (CBC with differential) + Modifier 91 (if repeated on the same day).
- Notes: Justify repeat testing with clinical progression.
