CPT 87804: Influenza Antigen Immunoassay, Visual Read

CPT code 87804 denotes a visually read immunoassay to detect influenza antigens from respiratory specimens such as nasal or throat swabs. As a commonly used point-of-care and laboratory test, it supports rapid clinical decision-making for patients presenting with influenza-like illness and factors into national infectious disease surveillance, outpatient care workflows, and laboratory billing volumes. Its use influences test-site resource allocation and payer coverage policies for acute respiratory infection management.

Key payers included in this analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise description of the clinical purpose and settings for 87804, an overview of common comparators and related antigen tests, and the typical payer landscape affecting coverage and claims processing. The publication also covers coding context relevant to clinicians and billing professionals, including bundled service considerations and commonly encountered clinical scenarios where a rapid influenza antigen immunoassay is selected over multiplex or molecular testing.

This summary serves clinicians, laboratory managers, and revenue cycle professionals seeking a national-level briefing on the clinical role and billing context of CPT code 87804, with guidance on what elements to verify for claims submission and payer policy alignment.

Billing Code Overview

CPT code 87804 describes an immunoassay with direct optical (visual) observation performed to detect influenza (flu) in a patient specimen. The test is typically run on throat or nasal swab specimens or nasal washings and yields a qualitative result through visually observed reaction in the assay.

Service Type: Infectious agent antigen detection — point-of-care/clinical laboratory immunoassay (visual read)

Typical Site of Service: Outpatient clinics, urgent care centers, physician offices, and clinical laboratories that process respiratory swab or wash specimens.

Clinical Context

A 28-year-old outpatient presents to a family medicine clinic in midwinter with 36 hours of fever, myalgias, sore throat, nasal congestion, and a dry cough. The clinician performs a focused respiratory exam, documents influenza-like illness, and collects a nasal swab for point-of-care antigen testing. The laboratory or clinic front-office analyst performs an immunoassay with direct optical (visual) observation using the collected nasal swab to detect influenza A and/or B. Results are documented in the medical record and communicated to the ordering clinician for clinical correlation and potential antiviral therapy initiation. Typical sites of service include outpatient clinics, urgent care centers, emergency departments, and hospital laboratories where rapid antigen testing is performed at the point of care or in a near-patient laboratory setting.

Coding Specifications

Modifier	Description	When to Use
`25`	Significant, separately identifiable evaluation and management service by the same physician on the same day of the procedure	Use when a distinct E/M visit is provided in addition to the influenza antigen test on the same day.
`26`	Professional component	Apply when billing only the professional component of the test (interpretation) separate from the technical component.

Taxonomy Code	Specialty	Notes
`291U00000X`	Clinical Medical Laboratory	Laboratory professionals who perform and report the immunoassay.
`207Q00000X`	Family Medicine Physician	Common ordering and interpreting clinicians in outpatient and urgent care settings.
`207R00000X`	Internal Medicine Physician	Primary care and hospital-based physicians who order and act on test results.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`J10.1`	Influenza with other respiratory manifestations, seasonal influenza virus identified	Positive antigen test supports the diagnosis when the seasonal influenza virus is identified and patient has upper respiratory symptoms.
`J11.1`	Influenza with other respiratory manifestations, virus not identified	Antigen testing may be negative or inconclusive; diagnosis may be clinical or require molecular testing when virus not identified.
`J09.X2`	Influenza due to identified novel influenza A virus with other respiratory manifestations	Used when a novel influenza A strain is identified; antigen testing may be part of initial evaluation but confirmation often requires specialized testing.
`J10.0`	Influenza with pneumonia, seasonal influenza virus identified	Positive influenza antigen test can support management in patients presenting with lower respiratory involvement and suspected influenza pneumonia.
`J11.0`	Influenza with pneumonia, virus not identified	Antigen testing may be negative in severe or later-stage disease; clinical correlation and additional testing are often required.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`87636`	Infectious agent antigen detection (multiplex) SARS–CoV‑2, influenza A, and influenza B	Multiplex antigen testing used when simultaneous detection of SARS‑CoV‑2 and influenza A/B is clinically indicated; may replace single-agent influenza antigen testing when broader screening is needed.
`87807`	Infectious agent antigen detection; respiratory syncytial virus (RSV)	Alternative or additional respiratory antigen test performed in similar clinical presentations, particularly in pediatrics and older adults, when RSV is a differential diagnosis.

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Summary & Overview