Current Procedural Terminology (CPT) codes are a standardized set of five-digit codes used across the United States healthcare system to report medical procedures and services to payers, such as insurance companies and government programs. Created and maintained by the American Medical Association (AMA), these codes ensure that healthcare providers and laboratories communicate procedures uniformly for billing and data analysis. CPT Code 87798 is a specific identifier within this system, designated for a particular type of laboratory test focused on detecting infectious agents. This code is unique because it is designed to capture services for which no more specific reporting mechanism currently exists.
Defining Code 87798
The full, official nomenclature for this code is “Infectious agent detection by nucleic acid (DNA or RNA), not otherwise specified; amplified probe technique, each organism.” This lengthy description defines the exact technology used and its application. It is categorized under the broader umbrella of Microbiology Procedures and Molecular Pathology, specifically targeting the genetic material of pathogens.
The phrase “not otherwise specified” (NOS) is the defining characteristic of CPT 87798, indicating its role as a transitional or “catch-all” code. A laboratory uses this code when a highly specific CPT code for a particular infectious agent, such as influenza or HIV, has not been established by the AMA. This code is reserved for tests that use an amplified probe technique to find the DNA or RNA of one organism when no dedicated code exists. It serves as a necessary mechanism for reporting novel or specialized tests until the coding system can catch up to scientific advancements.
Specific Use Cases in Molecular Diagnostics
The primary scenarios requiring the use of CPT 87798 involve the rapid evolution of molecular testing technology and the emergence of new pathogens. Laboratories must use this code for newly emerging infectious agents, such as novel strains of viruses or bacteria, for which the AMA has not yet published a dedicated, specific code. This mechanism allows testing for these agents to be billed promptly even before the national coding system is updated.
This code is also frequently utilized for certain highly specialized tests developed within a specific facility, known as Laboratory-Developed Tests (LDTs). For instance, a laboratory might create a unique semi-quantitative polymerase chain reaction (PCR) test for a specific combination of organisms causing bacterial vaginosis, where each organism’s detection lacks its own CPT code. In such cases, the laboratory reports multiple units of 87798 to account for each distinct organism being analyzed. The code bridges the gap between a new scientific discovery and the standardized billing practices required for reimbursement.
Essential Billing and Documentation Requirements
Because CPT 87798 is a non-specific code, its use requires significantly more detailed administrative work compared to established codes. Payers often lack predefined pricing or clear policies for a service described only as “not otherwise specified.” Consequently, laboratories must submit extensive documentation to support the medical necessity and technical details of the procedure performed.
This documentation typically includes a comprehensive procedure note that describes the exact methodology, the specific infectious agent targeted, and a justification for why a more specific CPT code could not be used. Without this detailed evidence, claims are highly susceptible to denial or requests for further information from the payer. In certain complex situations, laboratories may need to manually submit pricing information, as a national fee schedule for this unlisted service may not be available.
Status and Reimbursement Challenges
The inherent lack of specificity in CPT 87798 often translates directly into significant challenges for timely reimbursement. The non-specific nature of the code means that private and public payers frequently flag it for manual review, leading to delayed payment or outright claim denial. For the billing laboratory, this increases administrative costs, as staff must spend time appealing denials and providing the required extensive documentation.
This code is generally viewed as a temporary status code within the coding landscape. Laboratories prefer to transition away from 87798 as soon as the AMA establishes a specific CPT code for the test they are performing. While necessary for reporting novel and specialized molecular diagnostic services, the use of 87798 signals a higher degree of uncertainty regarding payment compared to established, defined codes.