Summary & Overview
CPT 87324: Clostridium difficile Toxin Immunoassay
CPT code 87324 represents an immunoassay laboratory test to detect one or more toxins produced by Clostridium difficile, commonly used to evaluate patients with suspected C. difficile infection. Nationally, this code is central to laboratory confirmation of toxin-mediated disease and affects inpatient and outpatient testing workflows, infection control decisions, and laboratory reimbursement processes.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of how 87324 is described clinically, typical sites of service, common payer coverage considerations, and the payer mix used in benchmarking. The publication outlines common modifiers associated with laboratory billing and highlights areas where policy updates or clinical practice patterns can influence utilization. Clinical context explains the role of toxin immunoassays versus other diagnostic modalities for Clostridium difficile.
The report supplies practical benchmarking and policy-oriented context for laboratory managers, billing professionals, and healthcare administrators seeking to understand coding, payer approaches, and where to look for documentation or billing variances. Data not available in the input is explicitly noted where applicable.
Billing Code Overview
CPT code 87324 describes a laboratory immunoassay performed by a lab analyst to detect one or more toxins produced by Clostridium difficile, using techniques such as enzyme immunoassay (EIA). This test identifies the presence of bacterial toxins in stool specimens and is used to support the clinical diagnosis of C. difficile infection.
Service Type: Laboratory diagnostic test — infectious disease toxin detection
Typical Site of Service: Clinical laboratory or hospital laboratory (inpatient or outpatient specimen processing)
Clinical & Coding Specifications
Clinical Context
A 68-year-old hospitalized patient on broad-spectrum antibiotics develops acute onset watery diarrhea, abdominal cramping, and a low-grade fever. The attending hospitalist orders stool testing to evaluate for Clostridioides difficile infection. A stool specimen is collected in the inpatient laboratory or on the acute care floor and transported to the hospital microbiology laboratory. A medical laboratory scientist performs an immunoassay (enzyme immunoassay, EIA) for detection of one or more C. difficile toxins as part of the diagnostic workup. Results are reported to the ordering provider and documented in the electronic medical record; a positive toxin EIA may prompt contact precautions, targeted therapy, and review of recent antibiotic exposure.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When reporting only the professional component of a laboratory test if the performing lab separates technical and professional components and a billing entity is claiming the physician interpretation portion. |
TC | Technical component | When reporting only the technical component (laboratory processing and analysis) performed by the facility or reference lab. |