2027 ICD-10-CM Diagnosis Code G01Meningitis in bacterial diseases classified elsewhere

ICD-10-CM Codes›G00–G99›G00-G09›G01

ICD-10-CM G01
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 23 through 24, 94 through 96, 791, 793. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 106 closely related codes. 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
Short Description
Meningitis in bacterial diseases classified elsewhere
Same as the full description in the CMS dataset.
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 diagnoses
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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G01: its own notes plus those printed at Chapter 6. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

  • 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)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 6 (G00-G99) Diseases of the nervous system applies to 700 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Code First

The underlying condition named in the note is sequenced before this code.

  • underlying disease

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name G01, its category, or a range that includes it.

Notes 1

These notes mention G01.

  • G09 Sequelae of inflammatory diseases of central nervous system
    Category G09 is to be used to indicate conditions whose primary classification is to G00-G08 as the cause of sequelae, themselves classifiable elsewhere. The 'sequelae' include conditions specified as residuals. names G00-G08, which includes this code

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About G01Overview

What is the ICD-10 code for meningitis in bacterial diseases classified elsewhere?

The ICD-10-CM code for meningitis in bacterial diseases classified elsewhere is G01. It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

What MS-DRG does G01 group to?

On inpatient claims, meningitis in bacterial diseases classified elsewhere maps to MS-DRG 793, 791, 24, 23, 96, 95, 94, with relative weights from 2.3173 to 5.7422 depending on complications. Higher weights mean higher Medicare reimbursement.

Is G01 a CC or MCC?

CMS lists G01 as an MCC (major complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 106 closely related codes in its exclusion list.

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.