G2164 HCPCS Reimbursement & Policy Benchmarks | OpenPayer

Summary & Overview

HCPCS G2164: Prior Influenza Vaccine Adverse Reaction

HCPCS Level II code G2164 documents that a patient had a prior influenza vaccine adverse reaction at any time before or during the measurement period. Nationally, this code matters for immunization quality reporting, patient safety documentation, and measure exclusions when influenza vaccination is assessed across populations. Accurate use of this code helps differentiate patients who are excluded from vaccination measures due to adverse reactions from those who are eligible.

Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise explanation of the code’s clinical meaning, typical service setting, and how it functions within immunization measurement and reporting. The publication also outlines common billing modifiers associated with related service lines, typical sites where the code is recorded, and the implications for quality measurement and claims processing. Where payer-specific policies or coverage nuances are relevant, they are summarized for national audiences. Data not available in the input is noted where applicable.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareG2164HCPCS Level IIinfluenza vaccinevaccine adverse reactionimmunization reportingquality measuresambulatory care

Billing Code Overview

HCPCS Level II code G2164 indicates that a patient had a prior influenza virus vaccine adverse reaction at any time before or during the measurement period. This code documents a historical or current adverse reaction to an influenza vaccine and is used to capture that clinical history in the record.

Service type: Vaccine-related adverse reaction documentation and exclusion from influenza vaccination measure
Typical site of service: Outpatient clinic or other ambulatory care settings where immunization status is assessed

Clinical & Coding Specifications

Clinical Context

A patient presents to an outpatient primary care clinic or immunization center requesting routine vaccination review. The chart documents a prior adverse reaction to an influenza vaccine that occurred before or during the measurement period. Typical workflow: clinician reviews immunization history and allergy/adverse event record, documents the prior influenza vaccine adverse reaction with date and reaction details, evaluates risk vs benefit for future influenza vaccination, considers contraindications or medical exemptions, and records counseling and plan in the medical record. Typical site of service: outpatient clinic, primary care office, public health immunization clinic, or specialty allergy/immunology clinic. Typical patient scenario: an adult with prior hives and shortness of breath within 24 hours of receiving an influenza vaccine two years earlier who now presents for preventive care; clinician documents the prior reaction, assigns appropriate diagnosis/contraindication coding, and records the decision whether to administer, defer, or refer for allergy evaluation.

Coding Specifications

Modifier	Description	When to Use
`22`	Increased procedural services	Use when additional work, time, or complexity is documented beyond the usual for counseling or care related to vaccine adverse reaction assessment.
`23`

HCPCS G8763: Hypertension Quality Measures Completed

HCPCS-G9313-AMOXICILLIN-NON-FIRST-LINE-DOCUMENTED-REASON

HCPCS G9313: Amoxicillin Not Prescribed as First-Line with Documented Reason

HCPCS-G9136-NON-HODGKIN-LYMPHOMA-TRANSFORMED-DISEASE-STATUS

HCPCS G9136: Non-Hodgkin Lymphoma, Transformed Disease Status

HCPCS-G9302-PROPHYLACTIC-ANTIBIOTIC-INCOMPLETE-INFUSION-BEFORE-TOURNIQUET

HCPCS G9302: Prophylactic Antibiotic Incomplete Infusion Before Tourniquet Inflation

HCPCS-G0519-DEMENTIA-PATIENT-CAREGIVER-DYAD-MANAGEMENT-LOW-COMPLEXITY

HCPCS G0519: Management of New Patient-Caregiver Dyad with Dementia, Low Complexity

HCPCS-G9809-HOSPICE-SERVICES-UTILIZATION

HCPCS G9809: Patients Using Hospice Services During Measurement Period

HCPCS-G9013-ESRD-BASIC-BUNDLE-LEVEL-I

HCPCS G9013: ESRD Demo Basic Bundle Level I

HCPCS-G9767-EVALUATION-ENDOVASCULAR-STROKE-TREATMENT-INPATIENT

HCPCS G9767: Evaluation for Endovascular Stroke Treatment in Hospitalized Patients

HCPCS-G9382-END-OF-LIFE-PLAN-NOT-REVIEWED-OR-OFFERED-ASSISTANCE

HCPCS G9382: End-of-Life Plan Not Reviewed or Assistance Not Offered

HCPCS-G2204-SCREENING-COLONOSCOPY-AGE-45-85

HCPCS G2204: Screening Colonoscopy for Patients Aged 45–85

Showing 1–10 of 1996

Taxonomy Code	Specialty	Notes
`208000000X`	Family Medicine	Common site for vaccine history review and adverse reaction documentation.
`207Q00000X`	Allergy & Immunology	Specialty for evaluation of vaccine adverse reactions and challenge testing.
`208D00000X`	Internal Medicine	Adult primary care providers who document vaccine reactions and manage vaccine decisions.
`363L00000X`	Public Health	Immunization clinics and public health nurses who maintain vaccine records and adverse event reporting.
`261QP0200X`	Nurse Practitioner	Advanced practice providers who frequently perform vaccine counseling and documentation.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`Z88.0`	Allergy status to penicillin	Data not specific to influenza vaccine; included for cross-reference when multiple vaccine or medication allergies are documented.
`T88.1XXA`	Other complications following immunization, initial encounter	Captures adverse events related to vaccination that require evaluation.
`T78.2XXA`	Anaphylactic shock, unspecified, initial encounter	Used if prior influenza vaccine reaction included anaphylaxis.
`T78.40XA`	Allergy, unspecified, initial encounter	General allergy diagnosis useful when documenting adverse reaction history prior to specific testing.
`Z91.038`	Patient has had an adverse reaction to other vaccines	Specific to documenting a history of vaccine adverse reaction when no specific code for influenza exists.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`90471`	Immunization administration (per single vaccine)	Used when influenza vaccine is administered; not used if vaccination is contraindicated due to prior adverse reaction.
`99406`	Smoking and tobacco use cessation counseling, intermediate, greater than 3 minutes up to 10 minutes	Data not directly related to vaccine adverse reaction; include only if counseling unrelated to vaccination is provided during the visit.
`99407`	Smoking and tobacco use cessation counseling, intensive, greater than 10 minutes	See note for `99406`.
`94760`	Noninvasive ear or pulse oximetry for oxygen saturation; single determination	May be used if acute respiratory symptoms occur during observation after vaccination or during evaluation of prior reaction.
`95004`	Allergen specific IgE intradermal tests, per test	Used when allergy testing (skin testing) is performed to evaluate suspected vaccine component allergy.
`95117`	Professional services for preparation and provision of antigens for allergy testing	Used when specialized preparation is required for vaccine component allergy testing.

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