Vol. 17 Issue 5
The Molecular Edge
Reimbursement For Molecular Pathology Assays
Reimbursement of molecular testing offers special opportunities for frustration. CPT* coding is inherently complex for assays other than infectious agents, often slow to anticipate or keep up with new technologies and poorly understood by payers. Fair evaluation of new (and even older) technologies in the Clinical Laboratory Fee Schedule (CLFS) has been difficult to achieve.
Here, "molecular" refers to laboratory tests directed at DNA or RNA targets but not proteins, the molecular products of genes. Fundamental techniques employed (e.g., polymerase chain reaction [PCR] amplification) are common to assays for a host of molecular applications across many areas of the clinical laboratory. Depending on the size and complexity of a clinical laboratory, it can make sense to consolidate molecular equipment and expertise into a "technical center of excellence" that works closely with individual laboratory sections. As a result, clinical expertise and liaisons can integrate a molecular result with other laboratory or clinical considerations.
Codes for molecular detection of microorganisms are found only on the CLFS; reimbursement for professional interpretation of routine or difficult samples is said to be a component of part A payment to the laboratory or hospital. Since microbiology-oriented assays may comprise a major component of molecular tests offered by a clinical laboratory, administrators and physicians may wish to stress this fact when negotiating a management contract for the laboratory.
Molecular microbiology codes resemble general clinical laboratory codes: Most are analyte-specific, even though within individual analytes there is typically further technical breakdown into three detection modes (direct probe, amplified probe, quantitative) that offer successively higher levels of reimbursement. Codes are also available for selected viral genotypes and phenotypes, antibiotic resistant organisms and multiplex testing.
CLFS reimbursement may or may not cover the cost of performing FDA-cleared or commercial analyte-specific reagent (ASR)-based, laboratory-developed assays, whereas true laboratory-developed tests typically provide a clear profit margin. Efforts to get uniform reimbursement for quantitative viral assays (HIV-1 is favorable, HCV and others less so) have been unsuccessful. An area of uncertainty is coding for multiplex assay panels, e.g. respiratory viruses.
Oncology and Inherited Diseases
This is the complex area of coding for molecular assays. Twenty-one codes in the 83890 - 83914 series describe distinct procedural steps in the preparation and assay of a single sample to yield a molecular result. For example, a simple assay using a PCR/restriction fragment length polymorphism (RFLP) approach for the factor V Leiden mutation would involve DNA preparation (83890), PCR amplification (83898), digestion of the amplification product with a restriction enzyme that recognizes the mutant sequence (83892), separation and visualization of digested product by gel electrophoresis (83894) followed by interpretation of the resulting pattern and preparation of a report (83912). When interpretation is performed by a licensed physician, 83912 is billed with a -26 modifier and paid from the Physician Fee schedule. The reimbursable amount is the sum of fee schedule values for each code. If a procedural step must be performed more than once, e.g., amplification of more than one region of a gene for analysis, it is appropriate to bill multiples of a CPT code.
Procedural codes allow for accurate coding over a wide range of molecular genetic and oncology assays of varying complexity, as well as reasonably seamless incorporation of new codes for new technologies. However, payers struggle with procedural codes because they are:
a) accustomed to single CPT codes for a given analyte,
b) don't have an easy way to identify the analyte(s) tested and
c) frequently do not understand the requirements of molecular testing as demonstrated by coverage policies that are incomplete or don't make sense medically or scientifically.
A PCR-based assay to detect lymphoma via T-cell gamma chain gene receptor rearrangement typically requires amplification of four target regions (83898 x 4 if each region is done independently) versus a single amplification to evaluate the presence or absence of the Val617Phe variant associated with myeloproliferative disorders. Imagine payer suspicion or disbelief when single CPT codes may be billed >100 times for a patient undergoing full gene sequence analysis for several genes in the work-up of a connective tissue disorder. A further complication arises because the same analyte measured on different platforms requires coding specific to the method employed, e.g., factor V Leiden by melt curve analysis (LightCycler® or Invader®technology. At the request of payers, a system of alphanumeric modifiers (genetic testing code modifiersappendix I in the CPT manual) was developed several years ago to allow for the identification of the particular gene being tested using procedural codes. To date, no payers have adopted the modifier system.
Molecular Cytogenetic Codes
Molecular cytogenetic codes for FISH studies are reasonably straightforward88365-88368 for studies on tissue sections and 88271-88275 for cell smears or touch preparations. Because of economic considerations, relatively new microarray codes (88384-88386), intended for tiered coding of platforms of successive density, are being used in multiples by laboratories even though those codes lack the word "each" in their description. Molecular tests are frequently the source of consultative requests from users to laboratory directors, so remember that codes 80500 and 80502 can be used for limited and more comprehensive clinical pathology consults, respectively. These require a separate clinician request for the pathologist's consultation regarding an abnormal laboratory result that requires medical judgment conveyed in a separate written consultative report.
Not surprisingly, molecular pathology CPT codes have not escaped the attention of the Centers for Medicare and Medicaid Services' (CMS) National Correct Coding Initiative edits, some of which make sense and others not. Whether there will be issues with Medically Unlikely Edits remains to be seen. Reimbursement levels vary broadly by carrier and coverage policies, and payers are beginning to start considering clinical utility and medical necessity justification for testing. Do not hesitate to challenge payer denials if these do not make sense for patient care. Remember that CMS, by statute, does not pay for screening tests.
Dr. Kant is professor of Pathology and Human Genetics and director, Division of Molecular Diagnostics at the University of Pittsburgh Medical Center.
*CPT is a registered trademark of the American Medical Association (AMA).