P23.9 — Congenital pneumonia, unspecified

BillableUnspecifiedMCC

Is P23.9 billable?

Yes, but P23.9 is an unspecified code. P23.9 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, P23.9 is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting P23.9 — the more specific alternatives are listed below.

More specific alternatives

P23.9 at a glance

Code	P23.9
Description	Congenital pneumonia, unspecified
Billable	Yes
Code set	ICD-10-CM FY2027
Valid for encounters	October 1, 2026 – September 30, 2027

Which MS-DRGs does P23.9 group to?

P23.9 sits in MDC 15 and helps define the logic of 1 MS-DRG (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.

791Prematurity with Major Problemsmedical

As a secondary diagnosis, P23.9 is a major complication or comorbidity (MCC), which can move a stay into a higher-paying DRG.

How is P23.9 listed in the Alphabetic Index?

These are the routes through the Alphabetic Index that lead to P23.9. They show the wording a clinician may have documented, which often differs from the Tabular description.

Pneumonia › congenital (acute) (double) (migratory) (purulent) (septic) (unresolved)
Pneumonia › neonatal (acute) (double) (migratory) (purulent) (septic) (unresolved)

Excludes1 — never code together — inherited from P23

The conditions below can never be reported together with P23.9 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.

neonatal pneumonia resulting from aspiration (P24.-)

Excludes2 — not included here — inherited from Chapter 16

The conditions below are not part of P23.9, but a patient may have both at the same time. When documentation supports it, P23.9 and the excluded code may both be reported.

congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
endocrine, nutritional and metabolic diseases (E00-E88)
injury, poisoning and certain other consequences of external causes (S00-T88)
neoplasms (C00-D49)
tetanus neonatorum (A33)

How long has P23.9 existed?

P23.9 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.

Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.

Which conditions are coded to P23.9?

ICD-10 code for Pneumonia