Advanced Search

Pathology/Lab Coding Alert

Here's How to Get All You Deserve for Stool Cultures

Published on Tue May 25, 2004

Case study: Test yourself by coding from culture to treatment

Stool cultures can be as simple as one plate/one code, or as complicated as multiple plates with additional identification and susceptibility tests.

Try your hand at stool cultures by coding the following scenario, then read our experts' solution and see how you did.

Scenario: A physician orders stool culture testing for a patient with diarrhea (787.91 , Diarrhea NOS). The lab requisition allows the physician to select from the following tests:

  •  Routine stool culture -- includes Salmonella, Shigella, and Campylobacter
  •  Select analyte specific test(s) for additional enteric pathogen(s)

    Yersinia 
    Vibrio
    E. Coli     0157

  •  Stool isolates may reflex to further identification and susceptibility tests, as indicated.

    The physician orders a routine stool culture and selects additional testing for Yersinia and Vibrio.

    The lab cultures the stool specimen for Salmonella, Shigella and also plates on Campylobacter media, CIN (celfsulodin-irgasan-novobiocin) selective agar for Yersinia, and TCBS (thiosulfate citrate bile sucrose) selective agar for Vibrio.

    The lab reports negative for Salmonella, Shigella, Campylobacter and Vibrio, positive for Yersinia spp. The lab then performs additional biochemical panels using BioMerieux API 20E and identifies the organism as Yersinia enterocolitica. The lab performs susceptibility studies using minimum inhibitory concentration (MIC) --five plates --and reports ciprofloxacin and norfloxacin susceptibility for the gastrointestinal infection.

    Solution: You should report each test performed, regardless of positive or negative results. CPT groups stool culture organisms differently than the lab's requisition form.

    You should bill according to the CPT groupings as follows:
  •  For Salmonella and Shigella testing as part of the routine stool culture, report 87045 (Culture, bacterial; stool, aerobic, with isolation and preliminary examination [e.g., KIA, LIA], Salmonella and Shigella species).
  •  For each additional organism plated - Campylobacter, Yersinia and Vibrio --report one unit of 87046 (Culture, bacterial; stool, aerobic, additional pathogens, isolation and presumptive identification of isolates, each plate).

    Follow your carrier's instructions for billing multiple units: 87046 x 3 or use modifier -59 (Distinct procedural service ) or modifier -91 (Repeat clinical diagnostic laboratory test).

    Because the AMA issued CPT 2004 errata that reinstated the phrase "each plate" in the 87046 code definition, you should report 87046 for each organism in addition to the original Salmonella and Shigella.
  •  List the definitive identification to Y. enterocolitica using BioMerieux API 20E as 87077 (Culture, bacterial; aerobic isolate, additional methods required for definitive identification, each isolate).
  •  For the susceptibility testing, use code 87186 (Susceptibility studies, antimicrobial agent; microdilution or agar dilution [minimum inhibitory concentration (MIC) or breakpoint], each multiantimicrobial, per plate). 

    -- The solution to this scenario was prepared with the help of Vickie Baselski, PhD, department of pathology, University of Tennessee Health Science Center in Memphis.

    • Other Articles in this issue of

    Pathology/Lab Coding Alert

    View All