Pathology/Lab Coding Alert

Unravel medical necessity.

Even if you consider microbiology culture coding an easy task, urine cultures can throw you for a loop. With dual codes only for urine, common sterile or polymicrobial findings, and the vagaries of medical necessity, there’s a lot to consider.

Let the following four questions lead you through your coding choices to make sure you crush your next urine culture case.

Question 1: How Do You Code Presumptive Identification?

When the lab receives a urine specimen for culture to isolate any organisms present that may be causing an infection, you should report the lab’s work using 87086 (Culture, bacterial; quantitative colony count, urine).

Based on colony growth, your coding can go two or more directions from here. If the culture shows no growth, you’re done. “Sterile urine specimens are not uncommon, so a negative culture will end the lab’s work at 87086,” says William Dettwyler, MT-AMT, president of Codus Medicus, a laboratory coding consulting firm in Salem, Ore.

On the other hand, if the culture results in colonies that need identification, the lab will proceed with specific steps to identify the organism. One of the ways to proceed is with presumptive identification, which you’d report as 87088 (… with isolation and presumptive identification of each isolate, urine). If the lab performs presumptive identification on more than one isolate from the urine culture, then you should report multiple units of 87088.

Glossary: Presumptive identification means that the lab identifies the organism based on colony characteristics such as growth on specific medium, morphology (form), gram stain, and the results of up to three other tests such as catalase, oxidase, indole, or urease.

Key: CPT^® provides just one code for culture and presumptive identification for cultures from any source other than urine. For instance, for a throat swab, you would report 87070 (… any other source except urine, blood or stool, aerobic, with isolation and presumptive identification of isolates) for the culture, whether or not the lab isolates and presumptively identifies an organism.

Question 2: What Code(s) Capture Definitive Identification?

Assuming the lab has isolated at least one organism, the ordering physician may need more specific identification than the presumptive testing designates. In that case the identification would be by “definitive identification” methods, so you wouldn’t report the presumptive identification code (87088) for the lab’s work. When the lab identifies an organism presumptively but also performs additional tests for definitive identification, you should bill only the definitive code, according to Dettwyler.

Because urine culture is set up as an aerobic culture, the correct definitive identification code is 87077 (... aerobic isolate, additional methods required for definitive identification, each isolate).

Glossary: Definitive identification involves classifying the organism to the genus or species level using more tests such as biochemical panels or slide cultures.

In the rare case that a clinician specifically requests an anaerobic urine culture and definitive identification, turn to 87076 (… anaerobic isolate, additional methods required for definitive identification, each isolate) instead of 87077.

Typing: Labs might provide even more specific isolate identification, called “typing.” For instance, Klebsiella pneumoniae is a common pathogen associated with hospital acquired urinary tract infections (UTIs), and clinicians may need to know if a hospital patient with a K. pneumonia infection has a type identified in that hospital setting.

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 the following:

• 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 (eg, agglutination grouping), per antiserum)
• 87149 (… identification by nucleic acid (DNA or RNA) probe)
• 87150 (… identification by nucleic acid (DNA or RNA) probe)
• 87152 (… identification by pulse field gel typing)
• 87158 (… other methods)

Plus: If any of these methods require concentration of the isolate, you can code that separately using 87015 (Concentration (any type), for infectious agents).