Pathology/Lab Coding Alert

The culture is just the beginning when your lab provides information about infectious organisms. To identify genus, species, type and antibiotic susceptibility can take several tests--and you should bill for each one.

Start With Presumptive Identification

Whether the culture comes from blood, stool or other sources, the first step the lab performs is presumptive identification of microorganisms isolated on the culture medium. CPT defines this first step as -identification by colony morphology, growth on selective media, Gram stains or up to three tests (e.g., catalase, oxidase, indole, urease).- Based on the culture source, some common codes for presumptive identification of bacteria are as follows:

- 87040--Culture, bacterial; blood, aerobic, with isolation and presumptive identification of isolates (includes anaerobic culture, if appropriate)
- 87046--- stool, aerobic, additional pathogens, with isolation and presumptive identification of isolates, each plate
- 87070--- any other source except urine, blood or stool, aerobic, with isolation and presumptive identification of isolates
- 87075--... any source, except blood, anaerobic with isolation and presumptive identification of isolates
- 87088--Culture, bacterial; with isolation and presumptive identification of each isolate, urine.

Code Definitive Identification, Too

If your lab performs additional testing to identify the infectious organism more specifically than a presumptive identification, you should report an additional code, says William Dettwyler, MT-AMT, president of Codus Medicus, a laboratory coding consulting firm in Salem, Ore. The next step is definitive identification, which CPT defines as -identification to the genus or species level that requires additional tests (e.g., biochemical panels, slide cultures).- Definitive identification includes these codes:

- 87076--Culture, bacterial; anaerobic isolate, additional methods required for definitive identification, each isolate
- 87077--... aerobic isolate, additional methods required for definitive identification, each isolate.

Get More Specific

That's not all. Labs might provide even more specific isolate identification, called -typing.- According to CPT, these additional studies might involve -molecular probes, chromatography, or immunologic techniques,- which you should report in addition to the presumptive and definitive identification codes. The culture typing codes include:

- 87140--Culture, typing; immunofluorescent method, each antiserum
- 87143--... gas liquid chromatography (GLC) or high-pressure liquid chromatography (HPLC) method
- 87147--- immunologic method, other than immunofluorescence (e.g., agglutination grouping), per antiserum
- 87149--- identification by nucleic acid probe
- 87152--- identification by pulse field gel typing
- 87158--- other methods.

Don't forget: If any of these methods require concentration of the isolate, you can code that separately using 87015 (Concentration [any type], for infectious agents).

Add on Susceptibility

If your lab performs susceptibility testing, you can report that service using an additional code. Your lab personnel might refer to these tests as -sensitivity tests,- but CPT calls the codes susceptibility studies, which you should report using one of the following codes:

- 87181--Susceptibility studies, antimicrobial agent; agar dilution method, per agent (e.g., antibiotic gradient strip)
- 87184--- disk method, per plate (12 or fewer agents)
- 87185--- enzyme detection (e.g., beta lactamase), per enzyme
- 87186--- microdilution or agar dilution (minimum inhibitory concentration [MIC] or breakpoint), each multi-antimicrobial, per plate
- +87187--... microdilution or agar dilution, minimum lethal concentration (MLC), each plate (list separately in addition to code for primary procedure)
- 87188--- macrobroth dilution method, each agent
- 87190--- mycobacteria, proportion method, each agent.