Pathology/Lab Coding Alert

Question: I've noticed that the National Correct Coding Initiative (NCCI) lists the codes for FNA interpretation (88173) and non-gyn thin layer preparation (88112) as mutually exclusive code pairs, but allows a modifier to override the edit. Under what circumstances can we bill 88173 and 88112 together?

Texas Subscriber

Answer: Because 88173 (Cytopathology, evaluation of fine needle aspirate; interpretation and report) and 88112 (Cytopathology, selective cellular enhancement technique with interpretation [e.g., liquid-based slide preparation method], except cervical or vaginal) both describe a cytopathology evaluation, you should select the one code that most closely describes the type of specimen your pathologist examined. You should not report the two codes together for a single fine needle aspiration (FNA).

Because NCCI lists a "1" in the modifier column for the 88173/88112 edit pair, you are correct that you can override the edit. But you shouldn't do so if you're describing the evaluation of a single specimen. You can only report 88173 with 88112 when you're describing two evaluations of two different specimens.

For example, if the pathologist evaluated both an FNA specimen from a breast lesion and a cellular-enhanced monolayer preparation from a urine specimen for the same patient on the same day, you can report the two codes together. You should override the edit pair by appending modifier -59 (Distinct procedural service).

CPT explains that modifier -59 describes procedures/services that you would not normally report together, but are appropriate under the circumstances. This may represent a different session or patient encounter, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury, according to CPT.

-- Reader Questions were prepared with the assistance of Laurie Castillo, MA, CPC, CPC-H, CCS-P, owner of Castillo Consulting in Manassas, Va.