2026 ICD-10-CM Diagnosis Code P91.819Neonatal encephalopathy, unspecified

ICD-10-CM Codes›P00–P96›P90-P96›P91

ICD-10-CM P91.819
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

P91.819 is a billable ICD-10-CM diagnosis code for neonatal encephalopathy, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neonatal cerebral disorders.

Code Identity

ICD-10-CM Code
P91.819
Billable Status
Yes — Valid for Submission
Code Describes
Neonatal encephalopathy, unspecified
Short Description
Neonatal encephalopathy, unspecified
Same as the full description in the CMS dataset.
Parent Code
P91.81
Neonatal encephalopathy

Code Classification

ChapterP00–P96Certain conditions originating in the perinatal period
SectionP90-P96Other disorders originating in the perinatal period
CategoryP91Other disturbances of cerebral status of newborn
This CodeP91.819Neonatal encephalopathy, unspecified

Present on Admission (POA)Billing

P91.819 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Axonal neuropathy
  • CNTNAP2-related developmental and epileptic encephalopathy
  • Coenzyme Q10 deficiency
  • Congenital axonal neuropathy with encephalopathy
  • Encephalopathy due to COVID-19
  • Encephalopathy, intracerebral calcification, retinal degeneration syndrome
  • Epileptic encephalopathy with global cerebral demyelination
  • Hypertrophic mitochondrial cardiomyopathy
  • Lethal neonatal spasticity, epileptic encephalopathy syndrome
  • MECP2 related disorder
  • Myoclonic epilepsy in non-progressive encephalopathy
  • Neonatal encephalomyopathy, cardiomyopathy, respiratory distress syndrome
  • Neonatal encephalopathy
  • SCN2A encephalopathy
  • SCN8A developmental and epileptic encephalopathy
  • Severe neonatal onset encephalopathy with microcephaly

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.

    • Encephalopathy(acute)
      • neonatal

Clinical ClassificationClinical

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

CCSR PNL004
Neonatal cerebral disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • GAIA Level 1 Neonatal Encephalopathy|Global Alignment of Immunization safety Assessment in pregnancy Level 1 Neonatal Encephalopathy|Level 1 Neonatal Encephalopathy

    gaia level 1 neonatal encephalopathy is defined by three criteria: first, a newborn infant (1-28 days of life) born at or beyond 35 weeks of gestation; second, an abnormal level of alertness or seizures; third, difficulty with initiating and maintaining respiration; fourth, depression of muscle tone.

  • GAIA Level 2 Neonatal Encephalopathy|Global Alignment of Immunization safety Assessment in pregnancy Level 2 Neonatal Encephalopathy|Level 2 Neonatal Encephalopathy

    gaia level 2 neonatal encephalopathy is defined by three criteria: first, a newborn infant (1 to 28 days of life) born at or beyond 35 weeks of gestation; second, an abnormal level of alertness or seizures; third, either difficulty with initiating and maintaining respiration or depression of muscle tone.

  • GAIA Level 3 Neonatal Encephalopathy|Global Alignment of Immunization safety Assessment in pregnancy Level 3 Neonatal Encephalopathy|Level 3 Neonatal Encephalopathy

    gaia level 3 neonatal encephalopathy is defined by three criteria: first, a newborn infant (1-28 days of life) born at or beyond 35 weeks of gestation; second, an abnormal level of alertness or seizures; third, none of the following: a) difficulty with initiating or maintaining respiration; b) depression of muscle tone.

  • GAIA Neonatal Encephalopathy Level of Diagnostic Certainty Terminology|Global Alignment of Immunization safety Assessment in pregnancy Neonatal Encephalopathy Level of Diagnostic Certainty

    a subset of terminology related to neonatal encephalopathy, developed by the global alignment of immunization safety assessment in pregnancy consortium to aid in monitoring and improving fetal and maternal outcomes.

  • GAIA Neonatal Encephalopathy Level of Diagnostic Certainty|Global Alignment of Immunization safety Assessment in pregnancy Neonatal Encephalopathy Level of Diagnostic Certainty|Neonatal Encephalopathy Level of Diagnostic Certainty

    a classification of maternal and fetal outcomes relating to neonatal encephalopathy, developed by the global alignment of immunization safety assessment in pregnancy, based on the extent to which the diagnosis has been confirmed.

  • Neonatal Encephalopathy

    abnormal functioning of the central nervous system in the newborn period that may be due to a variety of etiologies including hypoxia/ischemia, metabolic disturbance, or infection.

  • Severe Neonatal Encephalopathy Due to MECP2 Mutations

    an x-linked recessive condition caused by mutation(s) in the mecp2 gene, encoding methyl-cpg-binding protein 2. it is characterized by severe neonatal encephalopathy.

  • Acute Motor and Sensory Axonal Neuropathy|Acute Motor And Sensory Axonal Neuropathy|Acute Motor-Sensory Axonal Neuropathy|Acute Motor-Sensory Axonal Neuropathy

    a subtype of guillain-barre syndrome that targets sensory motor axons, and is characterized by acute onset of quadriparesis, distal sensory loss, areflexia, and respiratory insufficiency.

  • Acute Motor Axonal Neuropathy|AMAN

    a subtype of guillain-barre syndrome that targets motor axons, and is characterized by symmetric limb weakness, diffuse areflexia, facial and oropharyngeal muscle weakness, and respiratory insufficiency.

  • Axonal Neuropathy

    any nerve disorder affecting the axon of a nerve.

  • GAN wt Allele|GAN1|Giant Axonal Neuropathy (Gigaxonin) Gene|Gigaxonin wt Allele|KLHL16

    human gan wild-type allele is located in the vicinity of 16q24.1 and is approximately 65 kb in length. this allele, which encodes gigaxonin protein, is involved in both ubiquitination and neurofilament structure. mutation of the gene is associated with giant axonal neuropathy.

  • Giant Axonal Neuropathy

    a rare inherited disorder affecting the neurofilaments. it is caused by mutations in the gan gene. it is characterized by the presence of abnormally large nerve cell axons. signs and symptoms include difficulty walking, sensory disturbances, lack of motor coordination and abnormal reflexes in the limbs.

  • Spinocerebellar Ataxia, Autosomal Recessive, with Axonal Neuropathy 2|AOA2|Ataxia with Oculomotor Apraxia Type 2|SCAN2

    an autosomal recessive condition caused by mutation(s) in the setx gene, encoding probable helicase senataxin. it is characterized by juvenile onset progressive cerebellar ataxia, axonal sensorimotor peripheral neuropathy, and increased concentrations of serum alpha-fetoprotein. oculomotor apraxia is common, but is not always present.

  • Coenzyme Q10 Deficiency

    a genetically heterogeneous condition, typically inherited in an autosomal recessive fashion, characterized by coenzyme q10 deficiency.

Convert P91.819 to ICD-9-CMHistory

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

ICD-9-CM
779.1 NB cereb irrit NEC/NOS
Approximate The match is approximate rather than exact.

Code History & ChangesHistory

Replacement P91.819 replaces the following previously assigned code(s):

  • P91.8 - Other specified disturbances of cerebral status of newborn
FY 2018AddedAdded to the ICD-10-CM code setEffective October 1, 2017.
FY 2019–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About P91.819Overview

Is P91.819 (Neonatal encephalopathy) a billable code?

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

Is P91.819 exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for neonatal encephalopathy, unspecified on inpatient claims.

What is the ICD-9 equivalent of P91.819?

Under the General Equivalence Mappings, neonatal encephalopathy, unspecified converts to ICD-9-CM 779.1 (NB cereb irrit NEC/NOS). 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.