J40: ICD10 Code for Bronchitis, not specified as acute or chronic
J40 is the ICD10 code used for documenting Bronchitis, not specified as acute or chronic in clinical and billing records.

J40 refers to Bronchitis, not specified as acute or chronic, which includes chronic respiratory diseases that obstruct airflow and reduce lung function over time. These conditions are often progressive, affect daily breathing, and require ongoing management to prevent exacerbations.
Symptoms
- Persistent cough with or without sputum – Common in all chronic bronchitis cases (J40–J42)
- Shortness of breath – A hallmark of COPD, emphysema (J43), and asthma (J45)
- Wheezing – Characteristic of asthma (J45) and reactive airway diseases
- Chest tightness – Experienced in asthma and chronic bronchitis
- Frequent lung infections – Seen in bronchiectasis (J47)
- Declining lung function – Particularly relevant in chronic lung allograft dysfunction (J4A)
Diagnosis
Diagnosis of Bronchitis, not specified as acute or chronic involves spirometry, chest X-rays or CT scans, oxygen saturation testing, and patient history. In transplant cases (J4A), lung biopsy, pulmonary function trends, and imaging are essential to detect rejection or dysfunction.
ICD10 Code Usage
ICD10 code J40 is widely used by pulmonologists, internal medicine specialists, primary care physicians, and transplant teams. It helps guide treatment with inhalers, steroids, bronchodilators, oxygen therapy, pulmonary rehab, and transplant monitoring.
Related Codes
- J41 – Simple and mucopurulent chronic bronchitis
- J42 – Unspecified chronic bronchitis
- J43 – Emphysema
- J44 – Other chronic obstructive pulmonary disease
- J45 – Asthma
- J47 – Bronchiectasis
- J4A – Chronic lung allograft dysfunction
FAQs
Q1: What is ICD10 code J40?
A: It refers to Bronchitis, not specified as acute or chronic, a chronic lung condition that impairs breathing and requires ongoing management and sometimes hospitalization.
Q2: How does J40 differ from J41 or J42?
A: J40 is unspecified bronchitis; J41 and J42 are forms of chronic bronchitis, differentiated by mucus production and specificity.
Q3: Is asthma (J45) part of COPD?
A: No—while they share symptoms, asthma is typically reversible with treatment, whereas COPD (J44) is progressive and less reversible.
Q4: What is bronchiectasis (J47)?
A: It’s a condition where airways are permanently dilated due to infection or inflammation, leading to mucus buildup and recurrent infections.
Q5: Who manages these conditions?
A: Pulmonologists primarily, with support from respiratory therapists, transplant teams (for J4A), and primary care providers.
Conclusion
ICD10 code J40 is critical for managing and tracking Bronchitis, not specified as acute or chronic, supporting diagnosis, respiratory therapy, medication use, and patient outcomes in chronic lung diseases.

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