Pathology/Lab Coding Alert

Watch out for ‘multiplex.’

With burgeoning cases of respiratory syncytial virus (RSV) this winter season, you should make sure you hold the keys to proper procedure and diagnosis coding.

Study the following expert tips to ensure you’re on the right track for clean claims.

Look Far and Wide for RSV Lab Test Codes

If your lab performs a test for RSV infection, you won’t be able to turn to just one group of tests to select the best code. That’s because you’ll find codes for RSV tests in CPT^® Category I listings for antigen tests by many methods, or for an antibody test, as well several Proprietary Laboratory Analysis (PLA) codes.

Multiplex: You should also notice that in addition to tests specifically for RSV, many test codes evaluate a sample for multiple organisms simultaneously, which is a multiplex test.

Here’s a rundown of the codes you might need to know to select the most appropriate code for the test your lab performs.

RSV antigen tests: “Labs may use multiple methods to identify an infectious agent antigen in a specimen, including immunoassays and nucleic acid probes, among others,” says William Dettwyler, MT-AMT, president of Codus Medicus, a laboratory coding consulting firm in Salem, Oregon. Based on the lab method used, you have the following codes to choose from:

• 87420 (Infectious agent antigen detection by immunoassay technique (eg, enzyme immunoassay [EIA], enzyme-linked immunosorbent assay [ELISA], fluorescence immunoassay [FIA], immunochemiluminometric assay [IMCA]), qualitative or semiquantitative; respiratory syncytial virus)
• 87634 (Infectious agent detection by nucleic acid (DNA or RNA); respiratory syncytial virus, amplified probe technique)
• 87280 (Infectious agent antigen detection by immunofluorescent technique respiratory syncytial virus)
• 87807 (Infectious agent antigen detection by immunoassay with direct optical (ie, visual) observation; respiratory syncytial virus)

If a clinician wants to determine if the patient had a prior RSV infection, they may order an antibody test, which you should code as 86756 (Antibody; respiratory syncytial virus).

Multiple antigens: For tests that look for the presence of multiple pathogens, including RSV, you should look to one of the following codes in Category I:

• 87631 (Infectious agent detection by nucleic acid (DNA or RNA); respiratory virus (eg, adenovirus, influenza virus, coronavirus, metapneumovirus, parain­fluenza virus, respiratory syncytial virus, rhinovirus), includes multiplex reverse transcription, when performed, and multiplex amplified probe technique, multiple types or subtypes, 3-5 targets)
• 87632 (… respiratory virus (eg, adenovirus, influenza virus, coronavirus, metapneumovirus, parainfluenza virus, respiratory syncytial virus, rhinovirus), includes multiplex reverse transcription, when performed, and multiplex amplified probe technique, multiple types or subtypes, 6-11 targets)
• 87633 (… respiratory virus (eg, adenovirus, influenza virus, coronavirus, metapneumovirus, parainfluenza virus, respiratory syncytial virus, rhinovirus), includes multiplex reverse transcription, when performed, and multiplex amplified probe technique, multiple types or subtypes, 12-25 targets)
• 87637 (… severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (coronavirus disease [COVID-19]), influenza virus types A and B, and respiratory syncytial virus, multiplex amplified probe technique)

PLA codes: Several PLA codes also describe tests for multiple respiratory pathogens. The distinction is that these codes describe a single, proprietary test performed by a specific lab or using a specific manufacturer kit. That means you shouldn’t choose one of the following codes based on the description of the lab method, but should use the code only if your lab performs the proprietary test (name included below):

• 0202U (Infectious disease (bacterial or viral respiratory tract infection), pathogen-specific nucleic acid (DNA or RNA), 22 targets including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), qualitative RT-PCR, nasopharyngeal swab, each pathogen reported as detected or not detected) Proprietary name: BioFire^® FilmArray^® Respiratory Panel 2.1
• 0223U (Infectious disease (bacterial or viral respiratory tract infection), pathogen-specific nucleic acid (DNA or RNA), 22 targets including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), qualitative RT-PCR, nasopharyngeal swab, each pathogen reported as detected or not detected) Proprietary name: QIAstat–Dx^® Respiratory SARS CoV–2 Panel
• 0225U (Infectious disease (bacterial or viral respiratory tract infection) pathogen-specific DNA and RNA, 21 targets, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), amplified probe technique, including multiplex reverse transcription for RNA targets, each analyte reported as detected or not detected) Proprietary name: ePlex^® Respiratory Pathogen Panel 2, GenMark Dx,
• 0241U (Infectious disease (viral respiratory tract infection), pathogen-specific RNA, 4 targets (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2], influenza A, influenza B, respiratory syncytial virus [RSV]), upper respiratory specimen, each pathogen reported as detected or not detected) Proprietary name: Xpert^® Xpress SARS– CoV–2/Flu/RSV (all targets) from Cepheid

Remember: If your lab does perform one of the PLA tests, you must use the appropriate PLA code because they take precedence over CPT^® Category I codes.

Understand How RSV Infection Impacts Ordering Dx

Lab coders may not assign the final patient diagnosis, but they need to understand diagnoses they may see on a test requisition for RSV and how the diagnosis coding may impact medical necessity and coverage.

With that in mind, look at the following ICD-10-CM rules for reporting RSV infections:

Symptoms: Clinicians may order an RSV test, or a respiratory pathogen panel test based just on symptoms, such as the following:

• R05.1 (Acute cough)
• R06.02 (Shortness of breath)

Conditions: On the other hand, a physician may have diagnosed a patient with a specific condition, such as an ear infection, and request a lab test to drill down to the infectious agent involved. In that case, the ordering diagnosis may be the condition, such as one of the following:

• Middle ear infection, H65.- (Nonsuppurative otitis media)
• Upper respiratory disease, J06.9 (Acute upper respiratory infection, unspecified)

But if the lab test returns a positive RSV finding, the physician will need to add that information to the final diagnosis. “For generalized respiratory infections, otitis media, or other infection sites, coders are instructed to report two codes: one for the site of infection, and a second code, B97.4 (Respiratory syncytial virus as the cause of diseases classified elsewhere),” says Sheri Poe Bernard, CPC, CRC, CDEO, CCS-P, of Granite GRC Consulting in Salt Lake City.

Big 3: The most severe cases of RSV often settle in the lungs or bronchi. When the lab test confirms RSV as the causative agent for these conditions, the physician should report a single, specific ICD-10-CM code, as follows:

• Bronchitis: J20.5 (Acute bronchitis due to respiratory syncytial virus) is the correct code if the physician documents an acute case of bronchitis and a positive RSV test identifies the causative agent. Bronchitis occurs when the main airways in the lungs, known as bronchial tubes, become inflamed and cause the patient to cough. Often the bronchial tubes will fill with mucus, which loosens during a coughing bout.
• Bronchiolitis: J21.0 (Acute bronchiolitis due to respiratory syncytial virus) is the best code when a physician diagnoses a patient with acute bronchiolitis caused by an RSV infection. The condition is common in infants and young children, involving inflammation and congestion of the bronchioles (small airways) of the patient’s lungs.
• Pneumonia: Code J12.1 (Respiratory syncytial virus pneumonia) reports a documented case of pneumonia from RSV. One of the most common viral causes of pneumonia in the U.S. is RSV. Pneumonia is an infection in the lungs, and it is commonly caused by viruses or bacteria.