2027 ICD-10-CM Diagnosis Code A39.0Meningococcal meningitis

ICD-10-CM Codes›A00–B99›A30-A49›A39

ICD-10-CM A39.0
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

A39.0 is a billable ICD-10-CM diagnosis code for meningococcal 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. 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 49 closely related codes. Coders also document this condition as meningitis caused by gram-negative aerobic coccus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Meningitis.

Code Identity

ICD-10-CM Code
A39.0
Billable Status
Yes — Valid for Submission
Code Describes
Meningococcal meningitis
Short Description
Meningococcal meningitis
Same as the full description in the CMS dataset.
Parent Code
A39
Meningococcal infection

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA30-A49Other bacterial diseases
CategoryA39Meningococcal infection
This CodeA39.0Meningococcal meningitis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Meningitis caused by gram-negative aerobic coccus
  • Meningococcal meningitis

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to A39.0: its own notes plus those printed at Chapter 1. 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 Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • diseases generally recognized as communicable or transmissible

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 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • carrier or suspected carrier of infectious disease (Z22.-)
  • certain localized infections - see body system-related chapters
  • infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
  • infectious and parasitic diseases specific to the perinatal period (P35-P39)
  • influenza and other acute respiratory infections (J00-J22)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • code to identify resistance to antimicrobial drugs (Z16.-)

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name A39.0, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming A39.0: they are not reported together with it, unless the two conditions are unrelated.

  • G01 Meningitis in bacterial diseases classified elsewhere
    meningococcal (A39.0)

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, Meningococcal

    a fulminant infection of the meninges and subarachnoid fluid by the bacterium neisseria meningitidis, producing diffuse inflammation and peri-meningeal venous thromboses. clinical manifestations include fever, nuchal rigidity, seizures, severe headache, petechial rash, stupor, focal neurologic deficits, hydrocephalus, and coma. the organism is usually transmitted via nasopharyngeal secretions and is a leading cause of meningitis in children and young adults. organisms from neisseria meningitidis serogroups a, b, c, y, and w-135 have been reported to cause meningitis. (from adams et al., principles of neurology, 6th ed, pp689-701; curr opin pediatr 1998 feb;10(1):13-8)

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 A39.0 to ICD-9-CMHistory

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

ICD-9-CM
036.0 Meningococcal 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 A39.0Overview

What is the ICD-10 code for meningococcal meningitis?

The ICD-10-CM code for meningococcal meningitis is A39.0 (sometimes written as A390). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is A39.0 (Meningococcal infection) a billable code?

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

What MS-DRG does A39.0 group to?

When meningococcal meningitis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 24, 23, 96, 95, 94, with relative weights from 2.3173 to 5.7422 depending on complications. Higher weights mean higher Medicare reimbursement.

Is A39.0 a CC or MCC?

CMS lists A39.0 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 49 closely related codes in its exclusion list.

What is the ICD-9 equivalent of A39.0?

Under the General Equivalence Mappings, meningococcal meningitis converts to ICD-9-CM 036.0 (meningococcal meningitis). The mapping is a direct match.