2026 ICD-10-CM Diagnosis Code G01Meningitis in bacterial diseases classified elsewhere

ICD-10-CM CodesG00–G99G00-G09G01

ICD-10-CM G01
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G01 is a billable ICD-10-CM diagnosis code for meningitis in bacterial diseases classified elsewhere. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is a manifestation code that cannot be reported as the principal diagnosis. Coders also document this condition as meningitis caused by Nocardia. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Meningitis.

Code Identity

ICD-10-CM Code
G01
Billable Status
Yes — Valid for Submission
Code Describes
Meningitis in bacterial diseases classified elsewhere
Chapter
G00-G09
Inflammatory diseases of the central nervous system

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG00-G09Inflammatory diseases of the central nervous system
CategoryG01Meningitis in bacterial diseases classified elsewhere
This CodeG01Meningitis in bacterial diseases classified elsewhere

Code EditsBilling

Medicare Code Editor checks that affect claim validity for G01.

Manifestation codes describe the manifestation of an underlying disease, not the disease itself, and therefore should not be used as a principal diagnosis.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Meningitis caused by Nocardia

Tabular List NotesGuidance

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

Code First

  • underlying disease

Type 1 Excludes

  • meningitis (in):
  • gonococcal A54.81
  • leptospirosis A27.81
  • listeriosis A32.11
  • Lyme disease A69.21
  • meningococcal A39.0
  • neurosyphilis A52.13
  • tuberculosis A17.0
  • meningoencephalitis and meningomyelitis in bacterial diseases classified elsewhere G05

Clinical ClassificationClinical

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

CCSR INF003
Bacterial infections
Default principal diagnosis: inpatient No · outpatient No
CCSR NVS001
Meningitis
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Meningitis

Meningitis is inflammation of the thin tissue that surrounds the brain and spinal cord, called the meninges. There are several types of meningitis. The most common is viral meningitis. You get it when a virus enters the body through the nose or mouth and travels to the brain. Bacterial meningitis is rare but can be deadly.

Read the full article at MedlinePlus

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

Convert G01 to ICD-9-CMHistory

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

ICD-9-CM
320.7 Mening in oth bact dis
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 G01Overview

Is G01 (Meningitis in bacterial diseases classified elsewhere) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report meningitis in bacterial diseases classified elsewhere on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can G01 be a principal diagnosis?

No. This is a manifestation code: meningitis in bacterial diseases classified elsewhere describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.

What is the ICD-9 equivalent of G01?

Under the General Equivalence Mappings, meningitis in bacterial diseases classified elsewhere converts to ICD-9-CM 320.7 (mening in oth bact dis). 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.