Avoid negative impacts to your claims -- review billing and coding article A58918 molecular pathology and genetic testing

Molecular diagnostic testing and laboratory developed testing are rapidly evolving areas and thus present billing and coding challenges. Due to the rapid changes in this field, the CMS clinical laboratory fee schedule pricing methodology does not account for the unique characteristics of these tests. These challenges have led to services being incorrectly coded and improperly billed. It is the MAC’s responsibility to pay for services that are medically reasonable and necessary and coded correctly. The intent of this billing and coding article is to provide guidance for accurate coding and proper submission of claims.

The updates to CPT since 2013 that were to create a more granular, analyte and/or gene specific coding system, and to eliminate or greatly reduce “stacking” of codes has NOT resulted in the elimination or reduction of stacking of codes in billing. Rather the billing of multiple CPT codes for a unique molecular pathology or genetic test has significantly increased over the last two years. Coding issues have been identified throughout all the molecular pathology coding subgroups, but these issues of billing multiple CPT codes for a specific test have been significant in the Tier 2 (81403-81408) and not otherwise classified (81479) codes. Providers are expected to report the specific gene being tested in item 19 (CMS-1500 claim form) for Part B claims or the remarks field (UB-04 claim form) for Part A claims or the electronic equivalent on an electronic submission. Currently, medical records may be requested when CPT 81479 is reported and the service description narrative reported is not clear.

Updated April 8, 2025

The description of the service must be reported in the narrative section and must provide enough details for processing. If the description of the service is too large for the narrative field, a statement such as “refer to attached medical records” or “medical records attached” must be entered in the narrative field and records should be submitted with the initial claim submission. The narrative field must not be left blank. If we're unable to process the service based on remarks and no records are submitted to support the service billed, the service will be rejected (Part B) or the claim will be returned as unprocessable (Part A) and the claim must be resubmitted with the appropriate information.

Per Title 42 of the United States Code (USC) Section 1320c-5(a)(3), providers are required by law to “provide economical medical services and then, only where medically necessary.” In keeping with Title 42 of the USC Section 1320c-5(a)(3), claims inappropriately billed utilizing stacking or unbundling of services will be rejected or denied.

Read the billing and coding article (A58918) in its entirety to make sure you’re billing and coding these services correctly.