Summary & Overview
CPT 87190: Mycobacteria Susceptibility Testing, Proportion Method
CPT code 87190 codes for the technical laboratory procedure that evaluates a mycobacteria culture isolate’s susceptibility to an antimicrobial agent using the proportion method. This test is a specialized microbiology service used to guide treatment decisions for mycobacterial infections, including tuberculosis and non-tuberculous mycobacterial disease. Nationally, accurate and standardized susceptibility testing supports appropriate antimicrobial therapy, public health surveillance, and antimicrobial stewardship.
Key payers included in the analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise explanation of the clinical context for the service, typical sites of service, and the role of the proportion method in laboratory workflows. The publication also outlines common billing and coding considerations, expected service line placement for reporting, and typical modifiers used with laboratory technical services. Where payer-specific coverage patterns, reimbursement benchmarks, or policy updates exist, those items are summarized to inform billing and administrative teams.
This summary provides clinicians, laboratory managers, and billing professionals with the essential information to identify the procedure represented by CPT code 87190, understand its clinical relevance, and locate areas for further review of payer policies and laboratory protocols. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 87190 describes the laboratory technical procedure for assessing a mycobacteria culture isolate’s susceptibility to an antimicrobial agent using the proportion method. The service focuses on the technical steps performed by a laboratory analyst to determine whether a mycobacterial isolate is sensitive or resistant to a specific antibiotic.
Service type: Microbiology laboratory susceptibility testing (mycobacteria)
Typical site of service: Clinical or reference microbiology laboratory (inpatient or outpatient specimen processing areas)
Clinical & Coding Specifications
Clinical Context
A laboratory receives a respiratory specimen from a patient with suspected pulmonary mycobacterial infection after initial culture growth identifies a mycobacterial isolate. The specimen is cultured at a microbiology reference laboratory. A clinical laboratory scientist or medical technologist performs susceptibility testing using the proportion method to determine the isolate's sensitivity to first- and second-line antimycobacterial agents. Results guide infectious disease clinicians and pulmonologists in selecting effective therapy for infections such as pulmonary tuberculosis or non-tuberculous mycobacterial (NTM) disease. Typical workflow: specimen accessioning → isolate confirmation and identification (smear, culture, molecular ID) → set up proportion method susceptibility panels → incubate and read proportion plates/tubes → report minimum inhibitory concentrations or proportion-based susceptibility interpretations to the ordering clinician. Typical site of service: hospital clinical microbiology laboratory or regional reference laboratory performing mycobacterial susceptibility testing.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the professional interpretation/reporting component separate from technical work. |
TC |