Pathology/Lab Coding Alert

Don't report flow cytometry for clinical lab tests You'll need to learn a new way to use "unlisted antigen" code 86586 with CPT 2005's changes for immunology and flow cytometry coding. While you used to mix and match codes from immunology (86000s) with the flow cytometry code from cytopathology (88180 before 2005), that's no longer the way to go.

New way: Now you should use only immunology codes like 86064 and 86359 for immune-response cell-count studies that don't normally require a pathologist's interpretation - even if the method involves flow cytometry. Based on CPT 2005 code changes, you should use 86586 (Unlisted antigen, each) to report counts for unlisted cell types that are part of an immunodeficiency panel.

Reserve the new flow cytometry codes (88184-88189) for immunophenotyping of hematolymphoid cancers. These studies involve panels of markers that always require interpretation by a pathologist.

(See "Choose the Right Flow Cytometry Codes in 6 Easy Steps - Here's How" in the first article for a full discussion of the new flow cytometry codes.) Discover 86586 'Change' in CPT 2005 Depending on the publisher of your CPT book, you may or may not see 86586 listed as a changed code. But all versions of CPT 2005 show the same words that 86586 has always shown - Unlisted antigen, each.

What's changed in all versions is that CPT no longer indents 86586 under the "Skin test" code family. "From 1993, when 86586 was new, through 2004, CPT indented the code under 86485 (Skin test; candida), and 'unlisted' was not capitalized in the code definition," says Dennis Padget, MBA, CPA, FHFMA, president of DLPadget Enterprises Inc., a pathology business practices publishing company in Simpsonville, Ky. These CPT conventions meant that the full 86586 definition was Skin test; unlisted antigen, each.

Further, the AMA commented on code 86586 in the context of new immunology codes for B cells, natural killer cells, and stem cells. Under the heading "Immunology Rationale," CPT 2005 Changes: An Insider's View states, "Additionally, unlisted antigen code 86586 has been added and is intended to be reported for each antigen tested."

Don't miss: What does the 86586 change mean? "By removing 86586 from the skin-test family and commenting on the code in its immunology rationale, the AMA is saying that we should use 86586 for unlisted cell-types in immunodeficiency panels," Padget says. "The AMA's in-house coding advisers confirm that this is how we're to use 86586 today." Follow New Immunodeficiency-Panel Rules Labs often perform clinical cell analyses to evaluate a patient's immunologic status using methods that involve flow cytometry. To report these immunodeficiency panels, you should use clinical lab codes from the CPT immunology section (86000s), which Medicare pays under the Clinical Laboratory Fee Schedule. "Immunology codes describe quantitative [...]