2026 ICD-10-CM Diagnosis Code P23.1Congenital pneumonia due to Chlamydia

ICD-10-CM Codes›P00–P96›P19-P29›P23

ICD-10-CM P23.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

P23.1 is a billable ICD-10-CM diagnosis code for congenital pneumonia due to Chlamydia. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections, Perinatal infections, and Respiratory perinatal condition.

Code Identity

ICD-10-CM Code
P23.1
Billable Status
Yes — Valid for Submission
Code Describes
Congenital pneumonia due to Chlamydia
Short Description
Congenital pneumonia due to Chlamydia
Same as the full description in the CMS dataset.
Parent Code
P23
Congenital pneumonia

Code Classification

ChapterP00–P96Certain conditions originating in the perinatal period
SectionP19-P29Respiratory and cardiovascular disorders specific to the perinatal period
CategoryP23Congenital pneumonia
This CodeP23.1Congenital pneumonia due to Chlamydia

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Chlamydia pneumoniae infection
  • Congenital bacterial pneumonia
  • Congenital chlamydial pneumonia
  • Congenital pneumonia
  • Neonatal chlamydial infection
  • Neonatal chlamydial pneumonia
  • Neonatal pneumonia
  • Pneumonia caused by Chlamydia pneumoniae
  • Pneumonia caused by Chlamydiaceae

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • 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

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INF003
Bacterial infections
Default principal diagnosis: inpatient No · outpatient No
CCSR PNL009
Perinatal infections
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR PNL006
Respiratory perinatal condition
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Chlamydia Infections

Chlamydia is a common sexually transmitted infection (STI). It is caused by bacteria called Chlamydia trachomatis. Anyone can get chlamydia. It often doesn't cause symptoms, so people may not know that they have it. Antibiotics can cure it. But if it's not treated, chlamydia can cause serious health problems.

The full article covers:

  • What is chlamydia?
  • How is chlamydia spread?
  • Who is more likely to get chlamydia?
  • What are the symptoms of chlamydia?
  • How is chlamydia diagnosed?
  • Who should be tested for chlamydia?
  • What other problems can chlamydia cause?
  • What are the treatments for chlamydia?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert P23.1 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
770.0 Congenital pneumonia
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About P23.1Overview

Is P23.1 (Congenital pneumonia) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report congenital pneumonia due to Chlamydia on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of P23.1?

Under the General Equivalence Mappings, congenital pneumonia due to Chlamydia converts to ICD-9-CM 770.0 (congenital pneumonia). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.