2026 ICD-10-CM Diagnosis Code G31.81Alpers disease

ICD-10-CM Codes›G00–G99›G30-G32›G31

ICD-10-CM G31.81
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G31.81 is a billable ICD-10-CM diagnosis code for alpers disease. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as progressive neuronal degeneration of childhood. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neurocognitive disorders and Other nervous system disorders (often hereditary or degenerative).

Code Identity

ICD-10-CM Code
G31.81
Billable Status
Yes — Valid for Submission
Code Describes
Alpers disease
Short Description
Alpers disease
Same as the full description in the CMS dataset.
Parent Code
G31.8
Other specified degenerative diseases of nervous system

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG30-G32Other degenerative diseases of the nervous system
CategoryG31Other degenerative diseases of nervous system, not elsewhere classified
This CodeG31.81Alpers disease

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Progressive neuronal degeneration of childhood
  • Progressive sclerosing poliodystrophy

Tabular List NotesGuidance

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

Inclusion Terms

  • Grey-matter degeneration

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.

    • Alpers' disease
    • Degeneration, degenerative
      • grey matter (brain) (Alpers')

Clinical ClassificationClinical

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

CCSR NVS011
Neurocognitive disorders
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR NVS006
Other nervous system disorders (often hereditary or degenerative)
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Degenerative Nerve Diseases

Degenerative nerve diseases affect many of your body's activities, such as balance, movement, talking, breathing, and heart function. Many of these diseases are genetic. Sometimes the cause is a medical condition such as alcoholism, a tumor, or a stroke. Other causes may include toxins, chemicals, and viruses.

Read the full article at MedlinePlus

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

Convert G31.81 to ICD-9-CMHistory

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

ICD-9-CM
330.8 Cereb degen in child NEC
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 G31.81Overview

Is G31.81 (Other specified degenerative diseases of nervous system) a billable code?

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

What is the ICD-9 equivalent of G31.81?

Under the General Equivalence Mappings, alpers disease converts to ICD-9-CM 330.8 (cereb degen in child NEC). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.