Pathology/Lab Coding Alert

Ensure compliance with policy manual update.

When your lab bills codes from the range 87260-87899 (Infectious agent antigen detection…), you better scrutinize how you report multiple organisms if you don’t want to run afoul of Medicare policy.

Read on to learn how CMS updated instructions for these codes in chapter 10 of the 2017 NCCI Policy Manual in a way that might impact your coding (available at www.cms.gov/Medicare/Coding/NationalCorrectCodInitEd/index.html?redirect=/nationalcorrectcodinited/).

Focus: These rules concern only codes 87260-87660, according to the policy manual — but the code range for infectious agent antigen detection has since expanded to 87899. These codes describe infectious agent antigen (not antibody) detection from a primary source (such as blood or urine), not cultures or other sources. “CPT^® provides different codes for identifying infectious agents from other sources by immunology (antibody) or culture methods,” says William Dettwyler, MT AMT, president of Codus Medicus, a laboratory coding consulting firm in Salem, Ore.

Understand DOS MUE Edits

Medicare’s Medically Unlikely Edit (MUE) program lists the “maximum number of units of service (UOS) of a single code allowable by the same provider for the same beneficiary,” according to the policy manual.

Originally, all MUEs were adjudicated as claim-line edits, meaning that if you performed more than the allowed UOS of a single code, you could report the additional units on a separate claim line with modifier 59 (Distinct procedural service) to override the MUE limit.

Greet DOS edits: Beginning in 2013, CMS changed some MUEs from claim-line edits to date of service (DOS) edits. Your Medicare Administrative Contractor (MAC) adjudicates these per date by adding the units of a single code on all claim lines. That means you can never exceed the MUE for a single DOS.

Codes 87260-87660 moved to DOS edits in 2016, meaning that if units of a single code summed from all claim lines on a single date exceed the MUE, your MAC will deny all units of that code. You can’t use modifier 59 to override these DOS edits.

Know the number: The MUE for all codes in the range 87260-87660 is one, except for the following codes that have an MUE of two:

• 87300, Infectious agent antigen detection by immunofluorescent technique, polyvalent for multiple organisms, each polyvalent antiserum
• 87324, Infectious agent antigen detection by immunoassay technique, (e.g., enzyme immunoassay [EIA], enzyme-linked immunosorbent assay [ELISA], immunochemiluminometric assay [IMCA]) qualitative or semiquantitative, multiple-step method; Clostridium difficile toxin(s)
• 87328 … cryptosporidium
• 87329 … giardia
• 87385 … Histoplasma capsulatum
• 87400 … Influenza, A or B, each
• 87427 … Shiga-like toxin
• 87450 … single step method, not otherwise specified, each organism
• 87451 … multiple step method, polyvalent for multiple organisms, each polyvalent antiserum
• 87491 Infectious agent detection by nucleic acid (DNA or RNA); Chlamydia trachomatis, amplified probe technique
• 87493 … Clostridium difficile, toxin gene(s), amplified probe technique
• 87497 … cytomegalovirus, quantification
• 87592 … Neisseria gonorrhoeae, quantification
• 87530 … Herpes simplex virus, quantification
• 87551 … Mycobacteria species, amplified probe technique
• 87591 … Neisseria gonorrhoeae, amplified probe technique

Additionally, 87449 (Infectious agent antigen detection by immunoassay technique, (e.g., enzyme immunoassay [EIA], enzyme-linked immunosorbent assay [ELISA], immunochemiluminometric assay [IMCA]) qualitative or semiquantitative; multiple-step method, not otherwise specified, each organism) has an MUE of three.

Distinguish Procedure Vs. Organism

The infectious agent antigen detection codes describe a test procedure that identifies either a single organism, or multiple species/strains/types of an organism, or multiple organisms. If you use the same CPT^® code to describe more than one organism, species, strain, or type, you might be able to report multiple units of the code — emphasis on might.

Code per procedure: Recent NCCI Policy Manual updates emphasize that you should report just one code for one test procedure, even if you identify multiple organisms or types with that one test, as follows:

“If a single infectious agent antigen detection test procedure produces results for more than one species or strain of organism, report only one (1) code with one (1) unit of service (UOS) for the procedure. … A physician may report more than one UOS for testing different strains or species of an organism if and only if different test procedures are performed for the different strains or species. A physician should never report more UOS than the number of independent test procedures performed.”

Check Your Understanding With These Examples

Let’s look at some specific examples to see how these CMS policy statements and MUE numbers interact to impact your infectious agent antigen coding.

Example 1: The lab performs two separate antigen detection procedures using immunofluorescent technique and identifies adenovirus types 40 and 41 from a fecal specimen. The correct coding in this case is 87260 (Infectious agent antigen detection by immunofluorescent technique; adenovirus). Even though the lab performed two separate tests, the MUE for 87260 is one, so you cannot report multiple units of the test on the same DOS. Placing the codes on separate claim lines and using modifier 59 will not override the DOS MUE limit.

Example 2: When the lab performs two separate assays to identify Clostridium difficile toxin A and toxin B by enzyme immunoassay (EIA) you should report 87324 (Infectious agent antigen detection by immunoassay technique, [e.g., enzyme immunoassay (EIA), enzyme-linked immunosorbent assay (ELISA), immunochemiluminometric assay (IMCA)] qualitative or semiquantitative, multiple-step method; Clostridium difficile toxin[s]) for the first test, and 87324-59 for the second. That’s correct coding because the MUE for 87324 is two, and the documentation shows two separate EIA test procedures.

Example 3: The lab performs a polymerase chain reaction (PCR) test that distinguishes the presence of Bartonella henselae and Bartonella quintana. The correct coding for the service is 87471 (Infectious agent detection by nucleic acid (DNA or RNA); Bartonella henselae and Bartonella quintana, amplified probe technique). This is a single infectious agent detection test procedure that produces results for multiple species, plus the MUE for this code is one.

Example 4: If the lab tests for Influenza A and Influenza B using an ELISA test, you should bill 87400 (Infectious agent antigen detection by immunoassay technique, [e.g., enzyme immunoassay (EIA), enzyme-linked immunosorbent assay (ELISA), immunochemiluminometric assay (IMCA)] qualitative or semiquantitative, multiple-step method; Influenza, A or B, each). Additionally, you should bill 87400-59. The MUE value for code 87400 is two, and the code descriptor indicates that you should report a unit of the code for “each” type.