A39.0 Meningococcal meningitis

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

ICD-10-CM code A39.0 represents the diagnosis of meningococcal meningitis. Public health and clinical sources establish that meningitis is a primary syndrome of invasive meningococcal disease, an illness caused by the bacteria Neisseria meningitidis. This reference synthesizes coding details and clinical context from official public sources without providing personal medical advice. 4 5

What this code represents

In the ICD-10-CM system, code A39.0 is designated for the diagnosis of meningococcal meningitis. The World Health Organization ICD-10 version maps this code using a dagger symbol to indicate an etiology manifestation link with G01*. 5 6

Plain-language overview

Meningococcal disease is an uncommon but serious infection caused by the gram-negative bacteria Neisseria meningitidis. Meningitis is identified as one of the two most common syndromes associated with this invasive disease. 4

Clinical context

Clinical guidance notes that prompt diagnosis and treatment of meningococcal disease are important due to the risk of severe morbidity and death. Patients exhibiting symptoms of this disease should seek medical care immediately, regardless of vaccination status or antibiotic use. 3 4

Empiric treatment for suspected meningococcal disease includes an extended-spectrum cephalosporin, such as cefotaxime or ceftriaxone. If susceptibility of the meningococcal isolate to penicillin is confirmed, treatment can be switched to penicillin G or ampicillin. 3

Documentation considerations

Clinical sources indicate that laboratory markers for meningococcal meningitis include elevated cerebrospinal fluid, white blood cell count, peripheral blood leukocyte count, C-reactive protein, procalcitonin, and ESR. Hematologic and metabolic laboratory abnormalities are also characteristic of this condition. 2

Coverage and utilization context

A study analyzing pre-vaccination mortality in Brazil recorded 205 deaths assigned to code A39.0, accounting for 8.4 percent of 2,432 meningitis deaths. This research utilized A39.0 within the underlying cause of death field to track meningitis mortality. 1

What the sources add

While the clinical sources from the CDC describe the immediate medical management and syndromes of meningococcal disease, the mortality study from Brazil demonstrates the application of the A39.0 code in retrospective public health mortality tracking. 1 3

The National Library of Medicine Bookshelf identifies infants and adolescents as the two age groups most commonly seeing invasive meningococcal disease. This demographic detail adds clinical context to the populations affected by the diagnosis. 2

Sources

1. Combined effect of PCV10 and meningococcal C conjugate vaccination on meningitis mortality among children under five years of age in Brazil — pmc.ncbi.nlm.nih.gov; accessed 2026-07-25.
2. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-25.
3. Clinical Guidance for Meningococcal Disease — cdc.gov; accessed 2026-07-25.
4. Clinical Overview of Meningococcal Disease — cdc.gov; accessed 2026-07-25.
5. EVS Explore — evsexplore.semantics.cancer.gov; accessed 2026-07-25.
6. ICD-10 Version:2019 — icd.who.int; accessed 2026-07-25.