2026 ICD-10-CM Diagnosis Code P77.3Stage 3 necrotizing enterocolitis in newborn

ICD-10-CM Codes›P00–P96›P76-P78›P77

ICD-10-CM P77.3
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

P77.3 is a billable ICD-10-CM diagnosis code for stage 3 necrotizing enterocolitis in newborn. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as fetal and/or neonatal necrotizing enterocolitis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neonatal digestive and feeding disorders.

Code Identity

ICD-10-CM Code
P77.3
Billable Status
Yes — Valid for Submission
Code Describes
Stage 3 necrotizing enterocolitis in newborn
Short Description
Stage 3 necrotizing enterocolitis in newborn
Same as the full description in the CMS dataset.
Parent Code
P77
Necrotizing enterocolitis of newborn

Code Classification

ChapterP00–P96Certain conditions originating in the perinatal period
SectionP76-P78Digestive system disorders of newborn
CategoryP77Necrotizing enterocolitis of newborn
This CodeP77.3Stage 3 necrotizing enterocolitis in newborn

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Fetal and/or neonatal necrotizing enterocolitis
  • Necrotizing enterocolitis of newborn, stage 3A
  • Necrotizing enterocolitis of newborn, Stage 3B
  • Neonatal necrotizing enterocolitis

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Necrotizing enterocolitis with perforation
  • Necrotizing enterocolitis with pneumatosis and perforation

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.

    • Enterocolitis
      • necrotizing
        • in newborn
          • stage 3 (with pneumatosis, with perforation)

Clinical ClassificationClinical

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

CCSR PNL012
Neonatal digestive and feeding disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Premature Babies

Almost 1 of every 10 infants born in the United States are premature, or preemies. A premature birth is when a baby is born before 37 completed weeks of pregnancy. A full-term pregnancy is 40 weeks.

Read the full article at MedlinePlus

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

Convert P77.3 to ICD-9-CMHistory

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

ICD-9-CM
777.53 Stg III nec enterocol NB
Exact Match The mapping is direct, with no qualifiers.

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 P77.3Overview

Is P77.3 (Necrotizing enterocolitis of newborn) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report stage 3 necrotizing enterocolitis in newborn on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of P77.3?

Under the General Equivalence Mappings, stage 3 necrotizing enterocolitis in newborn converts to ICD-9-CM 777.53 (stg III nec enterocol NB). The mapping is a direct match.

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.