ICD-10 Logo
ICDxICD-10 Medical Coding
ICD-10 Logo
ICDxICD-10 Medical Coding
ICD 10 CodesDiagnoses
ICD 10 CodesDiagnoses
ICD-10 Logo
ICDxICD-10 Medical Coding

Comprehensive ICD-10-CM code reference with AI-powered search capabilities.

© 2025 ICD Code Compass. All rights reserved.

Browse

  • All Chapters
  • All Categories
  • Diagnoses

Tools

  • AI Code Search
ICD-10-CM codes are maintained by the CDC and CMS. This tool is for reference purposes only.
v1.0.0
ICD-10 Guide
ICD-10 CodesJ21.9

J21.9

Acute bronchiolitis, unspecified

BILLABLE STATUSYes
IMPLEMENTATION DATEOctober 1, 2015
LAST UPDATED09/06/2025

Code Description

ICD-10 J21.9 is a billable code used to indicate a diagnosis of acute bronchiolitis, unspecified.

Key Diagnostic Point:

Acute bronchiolitis, unspecified, is a common respiratory condition primarily affecting infants and young children, characterized by inflammation of the bronchioles, the small air passages in the lungs. Clinically, it presents with symptoms such as wheezing, coughing, shortness of breath, and difficulty breathing, often following a viral upper respiratory infection. The most common causative agents are respiratory syncytial virus (RSV) and other viral pathogens. The anatomy involved includes the bronchioles, which become obstructed due to inflammation and mucus production, leading to impaired airflow and gas exchange. Disease progression can vary; while many children recover within a week, some may develop severe respiratory distress requiring hospitalization. Diagnostic considerations include clinical evaluation of symptoms, history of exposure to respiratory infections, and, in some cases, chest X-rays or viral testing to rule out other conditions. Accurate diagnosis is crucial to differentiate acute bronchiolitis from other respiratory illnesses, such as asthma or pneumonia, which may require different management strategies.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Diagnostic complexity: Requires clinical assessment and sometimes additional testing to confirm
  • Treatment complexity: Management may vary from outpatient care to hospitalization based on severity
  • Documentation requirements: Detailed clinical notes are essential for accurate coding and reimbursement
  • Coding specificity: While J21.9 is a general code, specificity can improve with additional details about the patient's condition

Audit Risk Factors

  • Common coding errors: Misclassification with other respiratory conditions like asthma or pneumonia
  • Documentation gaps: Lack of detailed clinical notes may lead to denials or audits
  • Billing challenges: Variability in treatment approaches can complicate reimbursement

Specialty Focus

Medical Specialties

Pediatrics

Documentation Requirements

Standard ICD-10-CM documentation requirements apply

Common Clinical Scenarios

Various clinical presentations within this specialty area

Billing Considerations

Follow specialty-specific billing guidelines

Pulmonology

Documentation Requirements

Standard ICD-10-CM documentation requirements apply

Common Clinical Scenarios

Various clinical presentations within this specialty area

Billing Considerations

Follow specialty-specific billing guidelines

Related CPT Codes

CPT Code

Clinical Scenario

Documentation Requirements

CPT Code

Clinical Scenario

Documentation Requirements

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

Acute bronchiolitis significantly impacts pediatric populations, particularly infants under two years of age. It is a leading cause of hospitalization in this age group, affecting healthcare utilization patterns and resource allocation. Understanding the epidemiology of bronchiolitis, including seasonal peaks and risk factors, is essential for public health initiatives aimed at reducing morbidity. Quality measures related to bronchiolitis management focus on timely diagnosis, appropriate treatment, and minimizing unnecessary hospitalizations.

ICD-9 vs ICD-10

Acute bronchiolitis significantly impacts pediatric populations, particularly infants under two years of age. It is a leading cause of hospitalization in this age group, affecting healthcare utilization patterns and resource allocation. Understanding the epidemiology of bronchiolitis, including seasonal peaks and risk factors, is essential for public health initiatives aimed at reducing morbidity. Quality measures related to bronchiolitis management focus on timely diagnosis, appropriate treatment, and minimizing unnecessary hospitalizations.

Reimbursement & Billing Impact

Reimbursement considerations include the severity of the condition, which may necessitate inpatient care or outpatient management. Common documentation requirements include detailed notes on the patient's symptoms, treatment response, and any follow-up care. Billing challenges may arise from the need to differentiate between outpatient and inpatient services, as well as ensuring that the documentation supports the level of care provided. Familiarity with payer-specific guidelines can also help mitigate common denials related to this diagnosis.

Resources

Clinical References

  • •
    ICD-10 Official Guidelines for J00-J99
  • •
    Clinical Documentation Requirements

Coding & Billing References

  • •
    ICD-10 Official Guidelines for J00-J99
  • •
    Clinical Documentation Requirements

Frequently Asked Questions

What specific conditions are covered by J21.9?

J21.9 covers acute bronchiolitis that is not specified by the causative agent. It includes cases where the exact virus is unknown or when multiple viruses are involved, but does not include chronic conditions or other respiratory diseases.

When should J21.9 be used instead of related codes?

J21.9 should be used when the diagnosis of acute bronchiolitis is made without specification of the causative agent or when the clinical presentation aligns with bronchiolitis but does not meet the criteria for more specific codes.

What documentation supports J21.9?

Documentation should include a thorough clinical assessment, history of present illness, physical examination findings, and any relevant laboratory or imaging results that support the diagnosis of acute bronchiolitis.