Summary & Overview
CPT 87505: Multiplex Gastrointestinal Pathogen Panel, 3–5 Targets
CPT code 87505 represents a multiplex nucleic acid test that detects three to five gastrointestinal pathogens or subtypes using molecular techniques such as multiplex reverse transcription and amplified probe methods. This code covers assays that rapidly identify common enteric organisms — including Clostridium difficile, E. coli, Salmonella, Shigella, norovirus, and Giardia — and supports targeted clinical management and infection control efforts. Nationally, molecular enteric panels are important for timely diagnosis, outbreak detection, and appropriate antimicrobial stewardship.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication outlines payer coverage considerations, common modifier usage, and clinical contexts in which CPT code 87505 is applied.
Readers will learn the clinical scope of the code, typical sites of service, and operational context for laboratories performing the assay. The report also provides benchmarking and policy-relevant context where available, including how the test fits into diagnostic pathways for acute gastroenteritis and public health surveillance. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 87505 describes a laboratory test that detects three to five types or subtypes of gastrointestinal pathogens using nucleic acid detection methods. The assay may include multiplex reverse transcription and multiplex amplified probe techniques to identify organisms such as Clostridium difficile, Escherichia coli, Salmonella, Shigella, norovirus, and Giardia.
Service type: Multiplex nucleic acid pathogen panel.
Typical site of service: Clinical laboratory or hospital laboratory performing molecular diagnostic testing on gastrointestinal specimens.
Clinical & Coding Specifications
Clinical Context
A 28-year-old adult presents to an urgent care clinic with acute onset of watery diarrhea, abdominal cramping, nausea, and low-grade fever for 48 hours after a group meal. The clinician orders a multiplex gastrointestinal nucleic acid amplification test to detect common enteric pathogens. A stool specimen is collected and sent to the laboratory. The laboratory technologist performs a multiplex nucleic acid detection assay that identifies three to five bacterial, viral, or parasitic targets (for example, Clostridium difficile, Escherichia coli, Salmonella, Shigella, norovirus, Giardia) using amplified probe and/or reverse transcription techniques. Results are transmitted to the ordering provider; positive results guide isolation, antimicrobial therapy, public health reporting, and further clinical management. Typical sites of service include outpatient clinics, urgent care centers, hospital laboratories, and reference laboratories. Specimen handling, chain-of-custody, and laboratory quality controls are part of the workflow. Turnaround time is usually within hours to a couple of days depending on lab capabilities and courier transport.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the professional interpretation or supervision of a lab test separate from the technical component. |
TC | Technical component | Use when billing only the laboratory technical component (equipment, reagents, technologist time) of the test. |
91 | Repeat clinical diagnostic laboratory test | Use when the same test is repeated on the same day on the same patient for a valid medical reason. |
90 | Reference (outside) laboratory | Use when the performing lab is an outside reference laboratory and services are reported by the referring/facility laboratory. |
59 | Distinct procedural service | Use to indicate a separate and distinct laboratory service when bundling edits might apply (used rarely for labs). |
52 | Reduced services | Use when the laboratory performs a reduced service compared with the full test (document reason). |
53 | Discontinued procedure | Use when the test was started but discontinued for clinical reasons before completion. |
78 | Unplanned return to the operating/procedure room by the same physician following initial procedure for a related procedure | Rare for lab testing; may be used in related surgical cases when same provider returns for a related service. |
59 | Distinct procedural service | Duplicate entry avoided; listed above. |
90 | Reference laboratory | Duplicate entry avoided; listed above. |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
| 207Q00000X | Infectious Disease | Specialists who may order and interpret complex GI pathogen panels. |
| 207L00000X | Pathology & Laboratory Medicine | Pathologists oversee laboratory testing, quality and interpretation. |
| 163W00000X | Emergency Medicine | Emergency clinicians frequently order rapid GI pathogen panels for acute patients. |
| 208D00000X | Family Medicine | Primary care and urgent care clinicians commonly order testing for outpatient diarrhea. |
| 261QM0800X | Gastroenterology | Gastroenterologists may order panels for evaluation of infectious diarrhea versus other causes. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
A09 | Infectious gastroenteritis and colitis, unspecified | Common presenting diagnosis for acute infectious diarrhea prompting multiplex stool testing. |
A04.7 | Enterocolitis due to Clostridium difficile | Target pathogen for nucleic acid testing when C. difficile infection is suspected, especially after antibiotics. |
A08.0 | Rotaviral enteritis | Viral cause of acute gastroenteritis that may be included in multiplex panels using RT-PCR. |
A08.4 | Viral intestinal infection, unspecified | Use when viral etiology is suspected but specific virus not yet identified; multiplex testing can detect common viruses. |
A02.0 | Salmonella enteritis | Bacterial pathogen commonly targeted by GI multiplex panels. |
A03.0 | Shigellosis due to Shigella dysenteriae | Bacterial cause of inflammatory diarrhea included in many multiplex assays. |
A07.1 | Giardiasis | Parasitic infection detected by some multiplex molecular assays or by antigen testing. |
K52.9 | Noninfective gastroenteritis and colitis, unspecified | Included to differentiate infectious from noninfectious causes; negative multiplex results may support alternative diagnoses. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
87040 | Culture, bacterial; feces, routine, with isolation and presumptive identification of isolates | Performed when culture-based identification is required in addition to or following molecular testing. |
87449 | Infectious agent detection by nucleic acid (DNA or RNA); infectious agent not otherwise specified, multiple types or subtypes (multiplex), amplified probe technique, each organism | Alternative molecular assays for specific enteric pathogens when a different multiplex format or reporting structure is used. |
87471 | Infectious agent antigen detection by immunoassay technique, qualitative or semiquantitative, multiple-step method; Giardia | Performed when antigen-based testing for specific parasites is used instead of or alongside nucleic acid testing. |
87798 | Infectious agent antigen detection by immunoassay technique, multiple-step method, each antigen; not elsewhere classified | Use for other antigen assays that may complement multiplex nucleic acid testing. |
G0480 | Infectious agent detection by nucleic acid (DNA or RNA), multiple organisms, amplified probe technique; gastrointestinal pathogens (for certain payor or facility billing scenarios) | Used in some institutional or payor-specific billing situations as an alternate or aggregated code for multiplex GI pathogen panels. |