Pathology/Lab Coding Alert

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 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.

Did you know? 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.

Answer 2: Assuming the lab has isolated at least one organism, the ordering physician may need more specific identification than the presumptive testing designates. This definitive identification involves classifying the organism to the genus or species level using more tests such as biochemical panels or slide cultures.

In such cases, you won’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).

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, direct probe technique …)
• 87150 (… identification by nucleic acid (DNA or RNA) probe, amplified probe technique)
• 87152 (… identification by pulse field gel typing)
• 87158 (… other methods)

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

Remember: You should report the identification codes 87088 (presumptive) and 87077 (definitive) “per isolate,” so a case may include both codes and/or multiple units of the codes depending on how many culture isolates the lab identifies.

Caution: Urine cultures often result in polymicrobial isolates. That’s because nearby flora can easily contaminate urine specimens during collection.

“Isolation of three or more bacterial species from a urine culture usually indicates contamination, and labs generally won’t perform sensitivity testing in those cases because of uncertainty that any one of the organisms is a causing a UTI,” Dettwyler says.

Question 3: Once the lab has isolated and identified organisms from urine culture, the clinician may require further testing to indicate which antibiotic(s) are likely to be useful in treating the infection. That’s called sensitivity or susceptibility testing, and CPT^® provides the following codes to report the service:

• 87181 (Susceptibility studies, antimicrobial agent; agar dilution method, per agent (eg, antibiotic gradient strip))
• 87184 (… disk method, per plate (12 or fewer agents))
• 87185 (… enzyme detection (eg, 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)

Answer 4: Labs are at the mercy of the ordering clinician regarding what diagnoses you can report to indicate medical necessity for a urine culture. However, as a lab coder, it is useful for you to know the kinds of ICD-10-CM codes the ordering clinician will use to justify ordering a urine culture.

Physicians often order a urine culture following an in-office positive pyuria screen. In that case, the ordering diagnosis is R82.81 (Pyuria), which indicates white blood cells in the urine. The clinician may also order a urine culture based on other symptoms, such as pain associated with urination, coded to R30.0 (Dysuria); retention, coded to R33.- (Retention of urine); or frequency, coded to R35.0 (Frequency of micturition).