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P23.9 ICD-10-CM Code: Congenital pneumonia, unspecified

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
1 inclusion term · 1 Excludes1

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 791 — PREMATURITY WITH MAJOR PROBLEMS (MDC 15)
  • MS-DRG 793 — FULL TERM NEONATE WITH MAJOR PROBLEMS (MDC 15)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for P23.9 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on P23.9 itself; “inherited from” names the category or block whose note applies here.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • infective pneumonia acquired in utero or during birth

Source: inherited from P23

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from P23

Coder workflow for P23.9

MedCoder structured workflow — derived from this code’s own official record

Before you code P23.9

  1. Unspecified does not mean incorrect. When the record gives no greater specificity, P23.9 may be the appropriate code. Check the record for detail that supports a more specific sibling. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).

    ReviewP23.0, P23.1, P23.2, P23.3, P23.4, P23.5, P23.6, P23.8

    See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

  2. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with P23.9. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the record document the detail a more specific sibling code needs?
    Yes → Review the specific siblings in this subcategory.
    No → Continue — P23.9 is appropriate when the documentation goes no further.

    ReviewP23.0, P23.1, P23.2, P23.3, P23.4, P23.5, P23.6, P23.8

  2. Does the documentation support a condition named in P23.9’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewP24

Consider P23.9. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
Any detail beyond this code’s title
What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

  • Excludes1 — check before selecting P23.9(1 note)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with P23.9: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareP24

    See the official tabular notes · Guidelines I.A.12.a

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: The provider documents the condition in the terms of this code’s title and records no further detail.

Coding question: Is a more specific sibling code supportable?

Path: Review the specific siblings in this subcategory and what each requires the record to state.

Reason: A more specific code needs documentation of the distinguishing element; without it the unspecified code is appropriate, and a provider query is the route to specificity (Guidelines I.A.9.b, I.B.18).

ReviewP23.0, P23.1, P23.2, P23.3, P23.4, P23.5, P23.6, P23.8

Documentation: Both the condition P23.9 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewP24

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Congenital pneumonia, unspecified is a billable ICD-10-CM diagnosis code (P23.9).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (2)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Verify Before Coding

  • MCC as a secondary diagnosis (FY2026). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name P23.9 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 2 Excludes1 notes: J15 — Bacterial pneumonia, not elsewhere classified (via P23.-), J16 — Pneumonia due to other infectious organisms, not elsewhere classified (via P23.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 17 Excludes2 notes across 2 chapters: J09 — Influenza due to certain identified influenza viruses, J09-J18 — Influenza and pneumonia (J09-J18), J10 — Influenza due to other identified influenza virus, J11 — Influenza due to unidentified influenza virus, J12 — Viral pneumonia, not elsewhere classified, J13 — Pneumonia due to Streptococcus pneumoniae, J14 — Pneumonia due to Hemophilus influenzae, J15 — Bacterial pneumonia, not elsewhere classified, J16 — Pneumonia due to other infectious organisms, not elsewhere classified, J17 — Pneumonia in diseases classified elsewhere, J18 — Pneumonia, unspecified organism, P35 — Congenital viral diseases (via P23.-), P35-P39 — Infections specific to the perinatal period (P35-P39) (via P23.-), P36 — Bacterial sepsis of newborn (via P23.-), P37 — Other congenital infectious and parasitic diseases (via P23.-), P38 — Omphalitis of newborn (via P23.-), P39 — Other infections specific to the perinatal period (via P23.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: MCC — Major Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 68 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 2 MS-DRGs: DRG 791 (MDC 15), DRG 793 (MDC 15).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):PNL009 — Perinatal infections (default); PNL006 — Respiratory perinatal condition.

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical process (MS-DRG)

Acts as MCC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

P22.8 — Other respiratory distress of newborn, P22.9 — Respiratory distress of newborn, unspecified, P23.0 — Congenital pneumonia due to viral agent, P23.1 — Congenital pneumonia due to Chlamydia, 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, P23.8 — Congenital pneumonia due to other organisms, P24.00 — Meconium aspiration without respiratory symptoms, P24.01 — Meconium aspiration with respiratory symptoms, P24.10 — Neonatal aspiration of (clear) amniotic fluid and mucus without respiratory symptoms, P24.11 — Neonatal aspiration of (clear) amniotic fluid and mucus with respiratory symptoms, P24.20 — Neonatal aspiration of blood without respiratory symptoms, P24.21 — Neonatal aspiration of blood with respiratory symptoms, P24.30 — Neonatal aspiration of milk and regurgitated food without respiratory symptoms, P24.31 — Neonatal aspiration of milk and regurgitated food with respiratory symptoms, P24.80 — Other neonatal aspiration without respiratory symptoms, P24.81 — Other neonatal aspiration with respiratory symptoms, +47 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Perinatal infections, Respiratory perinatal condition).

A50.7 — Late congenital syphilis, unspecified, A50.9 — Congenital syphilis, unspecified, P23.0 — Congenital pneumonia due to viral agent, P23.1 — Congenital pneumonia due to Chlamydia, 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, P23.8 — Congenital pneumonia due to other organisms, P24.00 — Meconium aspiration without respiratory symptoms, P24.01 — Meconium aspiration with respiratory symptoms, P24.10 — Neonatal aspiration of (clear) amniotic fluid and mucus without respiratory symptoms, P24.11 — Neonatal aspiration of (clear) amniotic fluid and mucus with respiratory symptoms, P24.20 — Neonatal aspiration of blood without respiratory symptoms, P24.21 — Neonatal aspiration of blood with respiratory symptoms, P24.30 — Neonatal aspiration of milk and regurgitated food without respiratory symptoms, P24.31 — Neonatal aspiration of milk and regurgitated food with respiratory symptoms, P24.80 — Other neonatal aspiration without respiratory symptoms, P24.81 — Other neonatal aspiration with respiratory symptoms, +102 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Pneumonia”; these codes share that main term but sit in a different category of the Tabular List.

J84.111 — Idiopathic interstitial pneumonia, not otherwise specified (interstitial, chronic), J84.112 — Idiopathic pulmonary fibrosis (interstitial, usual), J84.113 — Idiopathic non-specific interstitial pneumonitis (interstitial, non-specific, idiopathic), J84.116 — Cryptogenic organizing pneumonia (cryptogenic organizing), J84.117 — Desquamative interstitial pneumonia (desquamative interstitial), J84.178 — Other interstitial pulmonary diseases with fibrosis in diseases classified elsewhere (interstitial, lymphocytic), J84.2 — Lymphoid interstitial pneumonia (lymphoid interstitial), J84.89 — Other specified interstitial pulmonary diseases (organizing), J84.9 — Interstitial pulmonary disease, unspecified (interstitial), J85.0 — Gangrene and necrosis of lung (necrotic), J85.1 — Abscess of lung with pneumonia (with, lung abscess), J95.4 — Chemical pneumonitis due to anesthesia (aspiration, postprocedural), J95.851 — Ventilator associated pneumonia (ventilator associated), J95.89 — Other postprocedural complications and disorders of respiratory system, not elsewhere classified (resulting from a procedure), P24.01 — Meconium aspiration with respiratory symptoms (meconium), P24.11 — Neonatal aspiration of (clear) amniotic fluid and mucus with respiratory symptoms (aspiration, newborn, mucus), P24.21 — Neonatal aspiration of blood with respiratory symptoms (aspiration, newborn, blood), P24.31 — Neonatal aspiration of milk and regurgitated food with respiratory symptoms (aspiration, newborn, milk), P24.81 — Other neonatal aspiration with respiratory symptoms (aspiration, newborn), T79.8 — Other early complications of trauma (traumatic), +74 more

Contextual Map

Every relationship of P23.9 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run P23.9 with these 9 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes

Referenced by Excludes2 notes (17)

Clinical classification (CCSR)

MS-DRG Grouper

  • MCC — Major Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (MCC).”— CMS MS-DRG Definitions Manual (Appendix C) · FY2026
  • DRG 791 — PREMATURITY WITH MAJOR PROBLEMS[MS-DRG]: “PREMATURITY WITH MAJOR PROBLEMS (MDC 15)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
  • DRG 793 — FULL TERM NEONATE WITH MAJOR PROBLEMS[MS-DRG]: “FULL TERM NEONATE WITH MAJOR PROBLEMS (MDC 15)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

Index entries

  • Pneumonia (acute) (double) (migratory) (purulent) (septic) (unresolved), congenital (infective)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Pneumonia (acute) (double) (migratory) (purulent) (septic) (unresolved), neonatal[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (9)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "P23.9 — Congenital pneumonia, unspecified." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/p23.9-congenital-pneumonia-unspecified

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Congenital pneumonia, unspecified

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to P23.9 in its code family, with their registry titles.

View all codes in the P23 family