Summary & Overview
CPT 87197: Bacterial Titer for Antibiotic Susceptibility
CPT code 87197 denotes a laboratory test in which a lab analyst performs a bacterial titer on patient serum to determine susceptibility to a specific antibiotic dosage. This test informs clinical decision-making by identifying whether a bacterial isolate is likely to respond to a particular antibiotic concentration and supports targeted antimicrobial therapy. Nationally, accurate reporting of such diagnostic procedures is important for laboratory reimbursement, surveillance of antimicrobial resistance patterns, and appropriate antibiotic stewardship.
Key payers commonly reviewed in national analyses include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of the clinical role of the test, typical sites of service, common billing modifiers, and what is available in the input about payer coverage. The publication summarizes standard coding practices, lists common modifiers associated with laboratory services, and notes when input data fields are not provided.
The content provides clinical context for laboratory and infectious disease teams, coding and billing staff, and policy analysts who need a concise reference for CPT code 87197. Data not available in the input is identified as such where applicable.
Billing Code Overview
CPT code 87197 describes a laboratory procedure in which a lab analyst performs a bacterial titer using patient serum to determine susceptibility to a specific antibiotic dosage. This service involves testing patient serum against bacterial organisms to assess whether a given antibiotic concentration is likely to inhibit or kill the organism.
Service type: Laboratory diagnostic test — antibiotic susceptibility/bacterial titer
Typical site of service: Clinical laboratory or hospital laboratory setting; specimen collection often occurs in outpatient clinics, hospitals, or ambulatory phlebotomy sites.
Clinical & Coding Specifications
Clinical Context
A 56-year-old patient presents with a bloodstream infection secondary to a suspected gram-negative organism. The inpatient infectious disease team orders a bacterial serum titer to determine the minimum inhibitory concentration (MIC) and the patient’s susceptibility to a targeted antibiotic dose. A venous blood specimen is collected and routed to the hospital microbiology laboratory. The lab technologist isolates the organism and a lab analyst performs a bacterial titer using the patient’s serum to determine susceptibility at specific antibiotic dosages. Results inform antimicrobial stewardship decisions, dosing adjustments, or a change in therapy. Typical site of service is the hospital clinical microbiology laboratory or an independent clinical laboratory supporting inpatient and outpatient providers. The clinical workflow includes specimen collection, receipt and accessioning, organism identification, preparation of serial dilutions or antibiotic concentrations, incubation, interpretation of titer endpoints, documentation in the laboratory information system, and result reporting to the ordering clinician.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When only the professional interpretation or report by a laboratory physician or pathologist is billed separately from the technical work |
TC |