2027 ICD-10-CM Diagnosis Code G00.1Pneumococcal meningitis

ICD-10-CM Codes›G00–G99›G00-G09›G00

ICD-10-CM G00.1
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

G00.1 is a billable ICD-10-CM diagnosis code for pneumococcal meningitis. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Meningitis.

Code Identity

ICD-10-CM Code
G00.1
Billable Status
Yes — Valid for Submission
Code Describes
Pneumococcal meningitis
Short Description
Pneumococcal meningitis
Same as the full description in the CMS dataset.
Parent Code
G00
Bacterial meningitis, not elsewhere classified

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG00-G09Inflammatory diseases of the central nervous system
CategoryG00Bacterial meningitis, not elsewhere classified
This CodeG00.1Pneumococcal meningitis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Pneumococcal meningitis
  • Streptococcal meningitis
  • Streptococcus infection of the central nervous system

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G00.1: its own notes plus those printed at G00 and Chapter 6. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From G00 Bacterial meningitis, not elsewhere classified applies to 6 codes
  • bacterial arachnoiditis
  • bacterial leptomeningitis
  • bacterial meningitis
  • bacterial pachymeningitis

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Meningitis due to Streptococcal pneumoniae

Excludes1

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

From G00 Bacterial meningitis, not elsewhere classified applies to 6 codes
  • bacterial meningoencephalitis (G04.2)
  • bacterial meningomyelitis (G04.2)

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)

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name G00.1, its category, or a range that includes it.

Use Additional Code 1

These codes say to use an additional code from the note, and G00.1 is one of the codes named.

  • D59.31 Infection-associated hemolytic-uremic syndrome
    Pneumococcal meningitis (G00.1)

Notes 1

These notes mention G00.1.

  • 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

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to 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 Yes · outpatient Yes

Clinical InformationClinical

  • Meningitis, Pneumococcal

    an acute purulent infection of the meninges and subarachnoid space caused by streptococcus pneumoniae, most prevalent in children and adults over the age of 60. this illness may be associated with otitis media; mastoiditis; sinusitis; respiratory tract infections; sickle cell disease (anemia, sickle cell); skull fractures; and other disorders. clinical manifestations include fever; headache; neck stiffness; and somnolence followed by seizures; focal neurologic deficits (notably deafness); and coma. (from miller et al., merritt's textbook of neurology, 9th ed, p111)

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 G00.1 to ICD-9-CMHistory

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

ICD-9-CM
320.1 Pneumococcal meningitis
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 G00.1Overview

What is the ICD-10 code for pneumococcal meningitis?

The ICD-10-CM code for pneumococcal meningitis is G00.1 (sometimes written as G001). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is G00.1 (Bacterial meningitis, not elsewhere classified) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report pneumococcal meningitis on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does G00.1 group to?

When pneumococcal meningitis is the principal diagnosis on an inpatient stay, it groups 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 G00.1 a CC or MCC?

CMS lists G00.1 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 G00.1 be reported with G04.2?

Not as a rule. The Excludes1 note at G00, which applies to G00.1, lists "bacterial meningoencephalitis (G04.2)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).