ICD-10 Code J16.0 – Chlamydial pneumonia (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J16.0 – Chlamydial pneumonia
What it is
J16.0 identifies pneumonia caused by Chlamydia species. Use it when the provider documents chlamydial pneumonia as the diagnosis, not just a suspected respiratory infection.
Clinical signs
Patients may have cough, fever, and other pneumonia findings on exam or imaging. Clinical features vary; refer to documentation for the organism and site of infection.
When to use this code
Use J16.0 when the medical record clearly states chlamydial pneumonia, including cases linked to documented chlamydial infection of the lower respiratory tract. It is appropriate when the provider attributes the pneumonia to Chlamydia. If the record only says pneumonia without an identified cause, check documentation.
Do not use for
Do not use this code for unspecified pneumonia, bronchitis, or upper respiratory infection. Do not assign it when chlamydia is mentioned without documentation of pneumonia.
Coding tip
Code the documented organism and infection site together; if the note is unclear, query for confirmation before assigning J16.0.