2026 ICD-10-CM Diagnosis Code P23.5Congenital pneumonia due to Pseudomonas

ICD-10-CM Codes›P00–P96›P19-P29›P23

ICD-10-CM P23.5
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

P23.5 is a billable ICD-10-CM diagnosis code for congenital pneumonia due to Pseudomonas. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 791, 793. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 68 closely related codes. Coders also document this condition as congenital bacterial pneumonia. 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
P23.5
Billable Status
Yes — Valid for Submission
Code Describes
Congenital pneumonia due to Pseudomonas
Short Description
Congenital pneumonia due to Pseudomonas
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 CodeP23.5Congenital pneumonia due to Pseudomonas

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Congenital bacterial pneumonia
  • Congenital pneumonia
  • Congenital pseudomonal pneumonia
  • Pneumonia caused by Pseudomonas

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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

Pneumonia

Pneumonia is an infection in one or both of your lungs. It causes the air sacs of your lungs to fill up with fluid or pus. Pneumonia can range from mild to severe, depending on what caused it, your age, and your overall health.

The full article covers:

  • What is pneumonia?
  • What causes pneumonia?
  • Who is more likely to develop pneumonia?
  • What are the symptoms of pneumonia?
  • What other problems can pneumonia cause?
  • How is pneumonia diagnosed?
  • What are the treatments for pneumonia?
  • Can pneumonia be prevented?

Read the full article at MedlinePlus

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

Convert P23.5 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 P23.5Overview

What is the ICD-10 code for congenital pneumonia due to Pseudomonas?

The ICD-10-CM code for congenital pneumonia due to Pseudomonas is P23.5 (sometimes written as P235). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is P23.5 (Congenital pneumonia) a billable code?

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

What MS-DRG does P23.5 group to?

When congenital pneumonia due to Pseudomonas is the principal diagnosis on an inpatient stay, it groups to MS-DRG 791, 793, with relative weights from 4.0590 to 4.1696 depending on complications. Higher weights mean higher Medicare reimbursement.

Is P23.5 a CC or MCC?

CMS lists P23.5 as an MCC (major complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 68 closely related codes in its exclusion list.

What is the ICD-9 equivalent of P23.5?

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