Summary & Overview
CPT 86309: Heterophile Antibody Immunoassay for Infectious Mononucleosis
CPT code 86309 denotes an immunoassay performed on serum or plasma to detect and titer heterophile antibodies commonly associated with infectious mononucleosis (IM). This laboratory test is diagnostically important for confirming suspected mono and guiding clinical decision-making in acute presentations. Nationally, accurate coding and reporting of this test affect laboratory billing, claims adjudication, and surveillance of mono-related care.
Key payers included in the analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of the clinical context for the assay, typical sites of service where the test is performed, and what to expect in payer coverage considerations. The publication presents benchmark information on utilization patterns, claim handling, and common modifier usage where available, along with concise policy and coding notes that impact reimbursement and compliance.
The report is intended for laboratory managers, billing specialists, and policy analysts seeking a national perspective on CPT code 86309, offering practical context on clinical use, billing implications, and areas where additional payer-specific guidance may be required. Data not available in the input for associated taxonomies, ICD-10 diagnoses, and related codes.
Billing Code Overview
CPT code 86309 describes an immunoassay for heterophile antibodies used to titer a patient’s serum or plasma for antibodies typically present in infectious mononucleosis (IM). The procedure is a laboratory diagnostic test that evaluates the presence and level of heterophile antibodies associated with mono.
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Service type: Laboratory diagnostic immunoassay
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Typical site of service: Clinical laboratory or hospital laboratory setting
Data not available in the input for associated taxonomies, ICD-10 diagnoses, and related codes.
Clinical & Coding Specifications
Clinical Context
A 19-year-old college student presents to an urgent care clinic with 10 days of fever, sore throat, posterior cervical lymphadenopathy, fatigue, and mild splenomegaly on exam. The clinician documents suspected infectious mononucleosis and orders serum testing for heterophile antibodies. A phlebotomist collects a blood specimen and sends it to the clinical laboratory. A laboratory technologist performs an immunoassay to detect and titer heterophile antibodies consistent with infectious mononucleosis. Results are reported back to the ordering provider and entered into the electronic health record; positive results may prompt counseling about activity restrictions (for example, avoiding contact sports if splenomegaly is present) and return-to-school guidance. Typical site of service is an outpatient clinic, urgent care, or hospital laboratory performing routine serologic testing.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | Unspecified | Rarely used; only if no other modifier applies and payer requires a default unspecified modifier. |
11 | Critical Care Service, Level I (not a standard modifier for labs but included in list) | Not applicable for this lab test; do not use for routine immunoassays. |