J16.0 Chlamydial pneumonia

Billable ICD-10-CM code, FY2026. Acts as a Major Complication or Comorbidity (MCC) as a secondary diagnosis.

Applies from J16 Pneumonia due to other infectious organisms, not elsewhere classified

Excludes1 (never code together)

• congenital pneumonia (P23.-)
• ornithosis (A70)
• pneumocystosis (B59)
• pneumonia NOS (J18.9)

Code first

• , if applicable, associated influenza (J09.X1, J10.0-, J11.0-)

Code also

• , if applicable, any associated condition such as:
• abscess (J85.1)
• aspiration pneumonia (J69.-)

MS-DRG index

Defines the logic of DRG(s) 193-195 in MDC 04.

Approximate ICD-9-CM (GEMs)

• 483.1 Pneumonia due to chlamydia

Code annotations containing back-references to J16.0

Back-references to J16.0

• Type 2 Excludes: A74 Other diseases caused by chlamydiae ("chlamydial pneumonia (J16.0)")
• Type 1 Excludes: J15 Bacterial pneumonia, not elsewhere classified ("chlamydial pneumonia (J16.0)")
• Type 1 Excludes: J17 Pneumonia in diseases classified elsewhere ("chlamydial pneumonia (J16.0)")

Back-references to J16

• Code Also: D81.82 Activated Phosphoinositide 3-kinase Delta Syndrome [APDS] ("pneumonia (J12-J18)")
• Use Additional: J95.89 Other postprocedural complications and disorders of respiratory system, not elsewhere classified ("bacterial or viral pneumonia (J12-J18)")

Diagnosis Index entries for J16.0

• Pneumonia (acute) (double) (migratory) (purulent) (septic) (unresolved) › chlamydial
• Pneumonia (acute) (double) (migratory) (purulent) (septic) (unresolved) › in (due to) › Chlamydia

Nearby codes

• J16 Pneumonia due to other infectious organisms, not elsewhere classified
• J16.0 Chlamydial pneumonia (this code)
• J16.8 Pneumonia due to other specified infectious organisms