J20.9 ICD-10 Code: Complete Guide for Acute Bronchitis, Unspecified

Acute bronchitis is a common respiratory condition that brings many patients to outpatient and primary care settings. It occurs when the bronchial tubes, which carry air in and out of the lungs, become inflamed. While the condition is typically short-term and resolves with rest and supportive care, proper documentation and coding remain essential.

The ICD-10 code J20.9, Acute bronchitis, unspecified, is used when the provider confirms acute bronchitis but the exact cause, whether viral, bacterial, or irritant, is not identified. Using this code accurately ensures precise reporting, supports treatment decisions, and helps reduce claim denials. This guide provides a complete overview of J20.9, including clinical relevance, coding details, documentation tips, and the role of specialists and billing support in managing care.

What is Acute Bronchitis

Acute bronchitis is a short-term inflammation of the bronchial tubes. These tubes help move air in and out of the lungs. When they become irritated or swollen, symptoms appear. 

Common symptoms include:

• Persistent cough
• Mucus or phlegm
• Chest discomfort
• Mild shortness of breath
• Wheezing
• Fatigue
• Mild fever
• Sore throat

The condition often starts after a cold or the flu. It usually lasts one to three weeks. Acute bronchitis often improves on its own with rest, fluids, and supportive care.

Common causes include:

The primary cause of acute bronchitis is a virus, but anything that irritates your airway can cause acute bronchitis.

• Common viruses include influenza, rhino virus, respiratory syncytial virus (RSV), and coronavirus.
• Bacteria that cause bronchitis include Bordetella pertussis, Mycoplasma pneumonia, and Chlamydia pneumonia.

Risk factors include:

• Active and passive smoking
• Exposure to lung irritants

 

ICD-10 Code for Acute Bronchitis, Unspecified 

The ICD-10, J20.9 code is used to report Acute Bronchitis, Unspecified, which means inflammation of the airway, but the specific infection cause (virus, bacteria, or irritant) is not identified.

• J20.9 – Acute bronchitis, Unspecified 

How ICD-10 Code J20.9 Is Built

ICD-10-CM codes are made of letters and numbers. Each part of the code gives specific information.

1. The first letter J

• Stands for Diseases of the respiratory system.

2. The category J20

• The next two numbers (20) identify a category.
• J20 = Acute bronchitis.

This category includes different types of acute bronchitis (viral, bacterial, etc.).

3. The decimal .9

• The number after the decimal shows specific details about the condition.
• .9 means unspecified the provider did not document the exact cause or type of acute bronchitis.

Types of Acute Bronchitis and Their ICD-10 Codes

Acute bronchitis has different types based on the infectious agent or cause. Each type has a different ICD-10 code.

1. Acute Bronchitis due to Mycoplasma pneumoniae

This form of acute bronchitis develops when the Mycoplasma pneumoniae bacterium irritates the bronchial tubes.

ICD-10 code:

• J20.0 – Acute Bronchitis due to Mycoplasma pneumoniae

2. Acute bronchitis due to Hemophilus influenzae

This form of acute bronchitis develops when the Hemophilus influenzae irritates or inflames the lower airways.

ICD-10 code:

• J20.1 – Acute Bronchitis due to Hemophilus influenzae

3. Acute Bronchitis due to Streptococcus

This form of acute bronchitis develops when Streptococcus bacteria inflame the bronchial passage.

ICD-10 Code:

• J20.2 – Acute Bronchitis due to Streptococcus

4. Acute Bronchitis due to Coxsackievirus

This form of acute bronchitis develops when the coxsackievirus affects the respiratory tract. 

ICD-10 Code:

• J20.3 – Acute Bronchitis due to Coxsackievirus

5. Acute Bronchitis due to Parainfluenza Virus

This form of acute bronchitis develops when the Parainfluenza virus irritates the airways.

ICD-10 Code:

• J20.4 – Acute Bronchitis due to Parainfluenza Virus

6. Acute Bronchitis due to Respiratory Syncytial Virus (RSV)

This form of acute bronchitis develops when the Respiratory Syncytial Virus causes irritation or swelling in the airways.

ICD-10 Code:

• J20.5 – Acute Bronchitis due to Respiratory Syncytial Virus (RSV)

7. Acute Bronchitis due to Rhinovirus

This form of acute bronchitis develops when the Rhinovirus causes inflammation of the bronchial tube.

ICD-10 Code:

• J20.6 – Acute Bronchitis due to Rhinovirus

8. Acute Bronchitis due to Echovirus 

This form of acute bronchitis develops when Echovirus infection triggers short-term airway irritation and coughing.

ICD-10 Code:

• J20.7 – Acute Bronchitis due to Echovirus

9. Acute Bronchitis due to other specified organisms

Used when bronchitis is caused by a known organism not listed in other categories.

ICD-10 Code:

• J20.8 – Acute Bronchitis due to other specified organisms

 

When the underlying cause is known, the accurate ICD-10 code for each type of acute bronchitis should be used to support proper documentation and reduce unnecessary  claim denials

Other ICD-10 Codes for this Condition

These additional ICD-10 codes help capture the symptoms or related respiratory issues that often show up with acute bronchitis, giving a fuller picture of what the patient is experiencing and supporting clearer documentation.

• R05.1 – Acute cough
  R05.1 ICD-10 code is used when the patient comes in with a sudden or persistent cough that’s hard to ignore.
• R06.2 – Wheezing
  R06.2 ICD-10 code is used when the patient has whistling or noisy breathing caused by irritated airways.
• R06.0 – Shortness of breath
  R06.0 ICD-10 code is used when the patient feels breathless or has trouble taking in enough air.
• R50.9 – Fever, unspecified
  R50.9 ICD-10 code is used when the patient has a fever, but the exact cause isn’t clear yet.
• J06.9 – Acute upper respiratory infection, unspecified
  J06.9 UCD-10 code is used when the patient has a general upper respiratory infection along with bronchitis symptoms.
• B34.9 – Viral infection, unspecified
  B34.9 ICD-10 code is used when a viral illness is suspected, but the specific virus hasn’t been identified.

 

If these conditions are present during the visit, they should be coded alongside the acute bronchitis diagnosis to ensure the patient’s symptoms and overall health picture are accurately documented.

If you’re also looking for ICD-10 guidance on Chronic Obstructive Pulmonary Disease (COPD), you can explore our detailed COPD ICD-10 article as well.

Coding Guidelines for Acute Bronchitis ICD-10

Accurate coding for acute bronchitis is essential to support clinical care, proper medical billing, and reporting. Key documentation elements providers should include:  

• Date of onset and duration of symptoms  
• Detailed description of cough and any wheezing  
• Presence of fever, shortness of breath, or chest discomfort  
• Any suspected or confirmed infectious agent  

 

The ICD-10 code J20.9 should be used only when the bronchitis is acute, and the specific infectious cause is not documented. If a causative organism is identified, select the corresponding J20 code (J20.0–J20.8). Always code additional symptoms (R05.1, R06.2, R06.0, R50.9) to provide a complete clinical picture.  

Role of the Cardiologist  

While acute bronchitis primarily affects the respiratory system, patients with existing heart conditions may require cardiology consultation. Persistent coughing and shortness of breath can place extra strain on the heart, particularly in patients with heart failure or arrhythmias. 

Cardiologists can:  

• Evaluate cardiac function in patients presenting with severe respiratory symptoms  
• Rule out cardiac causes of shortness of breath  
• Coordinate care with primary care providers to manage comorbid conditions  

How Liberty Liens Supports Coding Accuracy  

Medical billing services like Liberty Liens play a key role in ensuring proper ICD-10 coding and documentation. They help providers by:  

•  Reviewing patient charts for accurate and complete documentation  
•  Ensuring the correct ICD-10 codes are applied to reduce claim denials  
• Identifying missing symptom codes or secondary diagnoses  
• Streamlining revenue cycle management for more efficient claim submission  

 

If you’d like to learn more about Liberty Liens, check out our blog, Liberty Liens Your Complete Revenue Cycle Partner, for more insights

Conclusion  

Accurately documenting and coding acute bronchitis with ICD-10 code J20.9 ensures clear communication of the patient’s condition, supports appropriate treatment, and minimizes claim denials. By including detailed symptom information and using specific codes when the causative agent is known, providers create a complete clinical record. 

Collaboration with specialists, such as cardiologists for patients with underlying heart conditions, and support from medical billing experts like Liberty Liens, further strengthens care coordination and revenue management. Proper coding is not just a billing requirement. It’s an essential part of delivering safe, effective, and accountable patient care.