2025 CPT code 85009
(Active) Effective Date: N/A Revision Date: N/A Pathology and Laboratory Procedures - Manual Differential White Blood Cell Count Hematology and Coagulation Procedures Feed
Manual differential white blood cell count using the buffy coat method.
Modifiers may be applicable depending on the circumstances of service. Consult the CPT codebook and payer specific guidelines for appropriate modifier usage.
Medical necessity for a buffy coat smear is established when the physician has a clinical indication to investigate unusual cells or organisms in the peripheral blood that are not readily detected using other methods (e.g., automated differential). Examples include suspected infections by unusual pathogens or assessment for certain types of leukemia or lymphoma.This test is not always considered medically necessary if a standard complete blood count (CBC) with differential is sufficient.
The clinical responsibility lies with the laboratory analyst who performs all technical aspects of the test, from specimen collection and preparation to microscopic examination and cell counting and differentiation. The ordering physician is responsible for medical decision-making based on the results.
In simple words: A lab test where a technician manually counts different types of white blood cells in a blood sample. This involves spinning the blood to separate the cells, then examining and counting them under a microscope.
This CPT code (85009) represents a manual differential white blood cell (WBC) count performed using the buffy coat layer from a centrifuged blood specimen.The procedure involves centrifuging the blood sample to separate the components, extracting the buffy coat (the layer containing WBCs and platelets), preparing a smear, staining the slide, microscopic examination, and manual counting and differentiation of various WBC types. This method is less common than automated or manual differential WBC counts (85007), but may be used to identify unusual cells or organisms.
Example 1: A patient presents with suspected leukemia.The physician orders a buffy coat smear to assess for the presence of abnormal or immature white blood cells., A patient with a persistent fever of unknown origin undergoes a buffy coat examination to detect the presence of unusual microorganisms or atypical cells suggestive of infection., A patient with known immune deficiency is monitored for changes in WBC differential using this method to detect any significant shifts indicating infection or immune compromise.
The medical record must include the patient's clinical presentation, the physician's order for the test, the date and time of the specimen collection, the method used for collecting the specimen (e.g., venipuncture), the results of the manual differential WBC count with specific cell counts for each type (neutrophils, lymphocytes, monocytes, eosinophils, basophils), and any relevant interpretations or observations by the laboratory analyst.
** This test is less frequently used now due to the availability of automated differential WBC counts.Payers may require additional documentation to justify medical necessity.The collection of the blood specimen may be billed separately, using an appropriate CPT code for venipuncture or other collection methods (e.g., 36415).
- Revenue Code: T1D (LAB TESTS - BLOOD COUNTS)
- Payment Status: Active
- Modifier TC rule: The application of a technical component (TC) modifier depends on the specific payer's policies and whether the laboratory performing the test bills separately for the professional (26) and technical (TC) components.
- Specialties:Hematology, Pathology, Oncology, Infectious Disease
- Place of Service:Laboratory, Hospital (Inpatient or Outpatient), Physician's Office