Pathology/Lab Coding Alert

Question: When our lab performs flow cytometry to determine an HIV patient's T-cell count, how should we code for the interpretation since we only have one marker? The flow-cytometry interpretation codes start with "2 to 8 markers."


North Carolina Subscriber

Answer: You should not report an interpretation code for one flow-cytometry marker. You are correct that the interpretation codes begin at two--the codes are as follows:

88187--Flow cytometry, interpretation; 2 to 8 markers
88188--...9 to 15 markers
88189--...16 or more markers

Further, you should not use the flow cytometry codes at all for the test you describe--a total T-cell count--even if the lab uses flow-cytometry methodology. The proper coding for the procedure you describe is 86359 (T cells; total count).

CPT reserves the flow-cytometry codes (88184-88189) for panels run for immunophenotyping of potential hematolymphoid carcinomas.

For total-cell counts that stand alone or are part of immunology panels, such as T-cell counts for HIV patients, you should use the immunology codes. You should never use the flow-cytometry interpretation codes with the immunology total-count codes. The total counts do not require or involve physician interpretation.