Summary & Overview
HCPCS Level II M1300: Influenza Immunization Not Administered
HCPCS Level II code M1300 denotes that an influenza vaccine was not administered and the clinician documented the reason. This code captures clinical and operational circumstances—medical contraindication, patient refusal, or vaccine unavailability—that affect immunization delivery. Nationally, accurate use of this code matters for public health surveillance, quality measurement, and claims-level documentation of missed vaccinations during preventive encounters.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of how the code is used in practice, common settings where it appears, and implications for billing and quality reporting. The publication outlines benchmarks where available, explains typical service lines and sites of service, and summarizes the clinical context that justifies documented non-administration. Data gaps are noted where input information is incomplete.
This summary provides actionable clarity on code definition and use across payers, helping administrators, coders, and compliance teams understand when to expect M1300 on claims and what contextual documentation is required for accurate record keeping and reporting.
Billing Code Overview
HCPCS Level II code M1300 indicates that influenza immunization was not administered with the reason documented by the clinician. Examples of acceptable documentation include patient medical contraindication (such as allergy), patient declined or other patient reasons, and vaccine not available or other system reasons.
Service type: Immunization screening / vaccine administration encounter where immunization was not given.
Typical site of service: Outpatient clinic, primary care office, pharmacy immunization site, or other ambulatory care settings where influenza vaccination would normally be offered.
Clinical & Coding Specifications
Clinical Context
A patient presents to a primary care clinic during influenza season for a routine visit. The clinician reviews the patient’s immunization history and assesses for contraindications to influenza vaccine. The patient has a documented severe egg allergy and a recent history of Guillain-Barré syndrome within the past 6 weeks, and after discussion declines vaccination. The clinician documents the medical reason for non-administration and selects billing code M1300 for the visit to indicate that influenza immunization was not administered for reasons documented by clinician. The typical workflow includes screening for vaccination eligibility, counseling about risks and benefits, reviewing allergy and vaccine availability, documenting the reason for refusal or medical contraindication in the medical record, and coding the visit appropriately. Typical settings include ambulatory primary care clinics, urgent care centers, and community health centers where vaccine assessment occurs but the influenza immunization is not given due to patient allergy, patient refusal, or vaccine unavailability.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
22 | Increased procedural services | Use when additional documentation supports substantially greater work related to counseling or management around vaccine decision-making. |