November 11, 2002 - NCCI Version 9.1 CPT Coding Edits

The American Society for Microbiology (ASM) appreciates the opportunity to comment on the National Correct Coding Initiative (NCCI) edits proposed for implementation in Version 9.1 scheduled for April 1, 2003. The ASM is the largest educational, professional and scientific society with over 40,000 members dedicated to the promotion of the microbiological sciences and its application for the common good. Many of our members are directly involved in provision of microbiological and immunological diagnostic services to patients who qualify for federal programs including Medicare. Thus, we have a significant interest in insuring fair and appropriate reimbursement for reasonable and necessary services. We recognize the importance of processes like NCCI to promote correct coding and guarantee program integrity. Our comments are intended to identify specific circumstances in which the proposed edits may obstruct laboratory standards of care.

The first group of edits (Group I) proposed addresses "Infectious agent detection by nucleic acid (DNA or RNA)" with three possible methods defined for each microbial analyte. The "direct probe technique" refers to a method in which nucleic acids are detected without an initial amplification step, and the "amplified code technique" refers to a method in which either target, probe, or signal amplification has been used to improve absolute sensitivity of the assay over direct probe techniques. These assays are used in a qualitative manner to determine presence or absence of a clinically significant analyte. It would generally be unnecessary to perform these assay formats on the same sample for the same analyte on the same date of service. An exception would occur if more than one unique clinically significant nucleic acid sequence from the same organism specified in the CPT-4 descriptor were being tested. Modifier -59 (distinct procedural service) could be used to indicate this circumstance. The third format is "quantification" of nucleic acids detected in a clinical sample, generally using an amplified probe technique. These assays are generally used to monitor organism loads. It is possible that a qualitative assay for a specific organism by direct or amplified probe technique would be performed for diagnostic purposes, and if positive, followed by a quantification reflex on the same specimen from the same date of service to establish a baseline organism load prior to initiating antimicrobial therapy.

It should be noted that only a few assays meeting the CPT-4 descriptors for the category of "infectious agent detection by nucleic acid" are available as kits cleared for in vitro diagnosis or monitoring. Thus, it is difficult to identify every possible exception to the proposed edits at this point in time. However, we offer the following comments in response to your specific questions regarding appropriate utilization of these codes on the same specimen on the same date of service:

1. Appropriate use of direct probe and amplified code for a single analyte from a single specimen on the same date of service: Only one of these procedures would ordinarily be used to etiologically diagnose a condition. However, there are situations in which a replicate use of the same code or use of direct and amplified codes would be appropriate to detect more than one distinct clinically significant agent or nucleic acid sequence included in the same CPT code descriptor. For example, either 87528 or 87529 may be used twice on the same specimen to detect HSV types 1 and 2 using two different detection systems. Other examples of detection of different species of the same genus covered by the same code also exist (e.g. Candida species, 87480-87482 to detect C. albicans and C. tropicalis; Mycobacteria species to detect M. fortuitum and M. kansasii, 87550-87552).

2. Appropriate use of direct or amplified probe and quantification on the same date of service:Situations do exist in which a qualitative amplified nucleic acid assay would precede a quantification assay on the same specimen on the same date of service. Note that two codes (qualitative and quantitative) would only be used if two separate results were obtained. Those situations for which guidelines supporting this strategy currently exist are as follows:

  1. HIV testing: A patient with serologically confirmed HIV infection might have a sample from the same date of service tested for HIV quantification (only 87536 for HIV-1 or 87539 for HIV-2). This is compatible with coding guideline #6b in the NCD for HIV prognosis. If the quantification assay fails to detect viral RNA in this same patient, a test for proviral DNA (87534 or 87535 for HIV-1, or 87537 or 87538 for HIV-2) may be performed to rule-out the possibility of a nonspecific serological result. This is compatible with limitation #4 and coding guideline #6c in the NCD for HIV diagnosis.
  2. HCV testing: A patient with initial serologic evidence of HCV infection may have a confirmation performed by an alternate serologic assay (RIBA) or by a qualitative test for viral RNA (87521 or 87522). If positive, a quantification assay may be performed on the same sample (87522). Alternatively, a serologically confirmed high-risk patient may have only quantification performed. The selection of protocol for confirmation and reflex to quantification is based primarily on patient clinical risk factors. Both protocols are outlined in the NIH Consensus Statement on Management of Hepatitis C ( as well as in the "CDC Recommendations for Prevention and Control of Hepatitis C Virus Infection and HCV-Related Chronic Disease" published in Morbidity and Mortality Weekly Report (MMWR) RR-19 on October 16,1998 ( It is of particular note that the qualitative assays are generally more sensitive than quantitative assays, thus validating their use in patients likely to have low viral loads initially.
  3. CMV diagnosis and monitoring is indicated in immunocompromised patients or patients with established serious CMV infection who may undergo specific antiviral therapy. Similar to the situation with HCV, a CMV qualitative test (87495 or 87496) may be used to establish the presence of a virus with reflex to quantification to establish a baseline in positive patients. Alternatively, a patient with high clinical suspicion may have only the quantification assay performed. Unlike HCV, serology is not generally a reliable first-line assay for CMV infection, strengthening the role of molecular assays. A recent guideline validating the utility of these assays is available on request from ASM Press (Cumitech: Human Cytomegalovirus, 2002).
  4. Other agents: Any potentially latent infectious agent (e.g. HSV, EBV, Toxoplasma) may require a qualitative molecular diagnostic test with a reflex to a quantitative test. While specific guidance documents are not available, this concept is described in MMWR RR-10, October 20, 2000, "Guidelines for Preventing Opportunistic infections Among Hematopoietic Stem Cell Transplant Recipients."

The second group of edits (Group II) proposed involves different methods of testing for the same infectious organism in the CPT-4 code descriptor. In general, only a single nonculture dependent assay for direct, qualitative detection of a specific microbial analyte in a clinical specimen is necessary. Thus, for a specific microorganism in a specific specimen on the same day of service, one would select only one of the following assay formats as defined in CPT:

  • Infectious agent antigen detection by immunofluorescent technique
  • Infectious agent antigen detection by enzyme immunoassay
  • Infectious agent antigen detection by immunoassay with direct optical observation

ASM both understands and supports the CMS position that CMS should "not pay for multiple tests to determine the same clinical information" from the same specimen on the same date of service. The exceptions to the proposed code edits would represent either the use of a code pair to document the detection of more than one specific clinically significant analyte in the category defined in the descriptor, or if more than one assay format for the same analyte is used on more than specimen type. Both situations can be identified by the use of Modifier -59. Specific situations we have identified in which the stated codes may not be mutually exclusive are as follows:

  1. Codes for Chlamydia trachomatis and for Neisseria gonorrhoeae: It would be appropriate to use a code for an assay approved for genital samples simultaneously with one approved for use with conjunctival samples. Recent clarification of appropriate usage of the varying test formats for these two organisms can be found in MMWR RR-15, October 18, 2002, "Screening Tests to Detect Chlamydia trachomatis and Neisseria gonorrhoeae-2002."
  2. Qualitative assays reflexing to quantitative assays: As described in item #2b for Group I edits, it may be appropriate to qualitatively detect an agent by a qualitative test (antigen or nucleic acid detection), and reflex to a molecular quantification. Thus, CMV may be detected by an antigenemia test using 87332 or 87198 with a reflex to molecular quantification test 87497. The same principle might also apply to HSV and HBV.
  3. Codes for HBV: The qualitative detection of HBV DNA with or without quantification (87515, 87516, or 87517) is generally done to establish evidence of active viral replication. It does not eliminate the need to perform specific testing for HBeAg (87350) used as evidence of continuing infectivity or to replace HBsAg (87340) and the necessary surface antigen neutralization assay (87341), which is primary assay used in algorithms for testing for HBV infection staging. A current algorithm for HBV testing and test interpretation may be found in The ASM Manual of Clinical Immunology, 6th edition, 2002, Chapter 78, Viral Hepatitis.

ASM appreciates the opportunity to provide comments on these proposed NCCI edits and would be pleased to respond to any questions or requests for additional information.