P23.1 Congenital pneumonia due to Chlamydia

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

Applies from P23 Congenital pneumonia

Includes

• infective pneumonia acquired in utero or during birth

Excludes1 (never code together)

• neonatal pneumonia resulting from aspiration (P24.-)

MS-DRG index

Defines the logic of DRG(s) 791 in MDC 15.

Approximate ICD-9-CM (GEMs)

• 770.0 Congenital pneumonia (approximate)

Code annotations containing back-references to P23.1

Back-references to P23.1

• Type 1 Excludes: A56 Other sexually transmitted chlamydial diseases ("neonatal chlamydial pneumonia (P23.1)")
• Type 1 Excludes: A74 Other diseases caused by chlamydiae ("neonatal chlamydial pneumonia (P23.1)")

Back-references to P23

• Type 1 Excludes: J15 Bacterial pneumonia, not elsewhere classified ("congenital pneumonia (P23.-)")
• Type 1 Excludes: J16 Pneumonia due to other infectious organisms, not elsewhere classified ("congenital pneumonia (P23.-)")

Diagnosis Index entries for P23.1

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

Nearby codes

• P23 Congenital pneumonia
• P23.0 Congenital pneumonia due to viral agent
• P23.1 Congenital pneumonia due to Chlamydia (this code)
• P23.2 Congenital pneumonia due to staphylococcus
• P23.3 Congenital pneumonia due to streptococcus, group B
• P23.4 Congenital pneumonia due to Escherichia coli
• P23.5 Congenital pneumonia due to Pseudomonas
• P23.6 Congenital pneumonia due to other bacterial agents