2024 ICD-10-CM Diagnosis Code G03.9

Meningitis, unspecified

ICD-10-CM Code:
Short Description:
Meningitis, unspecified
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Not chronic
Code Navigator:

Code Classification

  • Diseases of the nervous system
    • Inflammatory diseases of the central nervous system
      • Meningitis due to other and unspecified causes

G03.9 is a billable diagnosis code used to specify a medical diagnosis of meningitis, unspecified. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2023 through September 30, 2024.

Unspecified diagnosis codes like G03.9 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Acute meningitis
  • Adhesive arachnoiditis
  • Arachnoiditis
  • Basilar meningitis
  • Chronic bilateral vestibulopathy due to and following meningitis
  • Decreased flexion
  • Hemorrhagic meningitis
  • Immunoglobulin G4 related disease
  • Immunoglobulin G4 related pachymeningitis
  • Leptomeningitis
  • Malignant meningitis
  • Meningitis
  • Meningitis following procedure
  • Meningomyelitis
  • Metastatic malignant neoplasm of meninges
  • Neonatal meningitis
  • Non-infective meningitis
  • Nuchal rigidity
  • Nuchal rigidity due to meningitis
  • Pachymeningitis
  • Postoperative meningitis
  • Posttraumatic meningitis
  • Sequelae of meningitis
  • Spinal arachnoiditis
  • Spinal effusion
  • Subdural effusion

Clinical Classification

Clinical Information

  • Malaria, Cerebral

    a condition characterized by somnolence or coma in the presence of an acute infection with plasmodium falciparum (and rarely other plasmodium species). initial clinical manifestations include headaches; seizures; and alterations of mentation followed by a rapid progression to coma. pathologic features include cerebral capillaries filled with parasitized erythrocytes and multiple small foci of cortical and subcortical necrosis. (from adams et al., principles of neurology, 6th ed, p136)
  • Meningeal Carcinomatosis

    primary or secondary neoplasm in the arachnoid or subarachnoid space. it appears as a diffuse fibrotic thickening of the meninges associated with variable degrees of inflammation.
  • Meningism

    a condition characterized by neck stiffness, headache, and other symptoms suggestive of meningeal irritation, but without actual inflammation of the meninges (meningitis). spinal fluid pressure may be elevated but spinal fluid is normal. (dejong, the neurologic examination, 4th ed, p673)
  • Meningitis

    inflammation of the coverings of the brain and/or spinal cord, which consist of the pia mater; arachnoid; and dura mater. infections (viral, bacterial, and fungal) are the most common causes of this condition, but subarachnoid hemorrhage (hemorrhages, subarachnoid), chemical irritation (chemical meningitis), granulomatous conditions, neoplastic conditions (carcinomatous meningitis), and other inflammatory conditions may produce this syndrome. (from joynt, clinical neurology, 1994, ch24, p6)
  • Meningitis, Aseptic

    a syndrome characterized by headache, neck stiffness, low grade fever, and csf lymphocytic pleocytosis in the absence of an acute bacterial pathogen. viral meningitis is the most frequent cause although mycoplasma infections; rickettsia infections; diagnostic or therapeutic procedures; neoplastic processes; septic perimeningeal foci; and other conditions may result in this syndrome. (from adams et al., principles of neurology, 6th ed, p745)
  • Meningitis, Bacterial

    bacterial infections of the leptomeninges and subarachnoid space, frequently involving the cerebral cortex, cranial nerves, cerebral blood vessels, spinal cord, and nerve roots.
  • Meningitis, Cryptococcal

    meningeal inflammation produced by cryptococcus neoformans, an encapsulated yeast that tends to infect individuals with acquired immunodeficiency syndrome and other immunocompromised states. the organism enters the body through the respiratory tract, but symptomatic infections are usually limited to the lungs and nervous system. the organism may also produce parenchymal brain lesions (torulomas). clinically, the course is subacute and may feature headache; nausea; photophobia; focal neurologic deficits; seizures; cranial neuropathies; and hydrocephalus. (from adams et al., principles of neurology, 6th ed, pp721-2)
  • Meningitis, Escherichia coli

    a form of gram-negative meningitis that tends to occur in neonates, in association with anatomical abnormalities (which feature communication between the meninges and cutaneous structures) or as opportunistic infections in association with immunologic deficiency syndromes. in premature neonates the clinical presentation may be limited to anorexia; vomiting; lethargy; or respiratory distress. full-term infants may have as additional features fever; seizures; and bulging of the anterior fontanelle. (from menkes, textbook of child neurology, 5th ed, pp398-400)
  • Meningitis, Fungal

    meningitis caused by fungal agents which may occur as opportunistic infections or arise in immunocompetent hosts.
  • Meningitis, Haemophilus

    infections of the nervous system caused by bacteria of the genus haemophilus, and marked by prominent inflammation of the meninges. haemophilus influenzae type b is the most common causative organism. the condition primarily affects children under 6 years of age but may occur in adults.
  • Meningitis, Listeria

    inflammation of the meninges caused by listeria monocytogenes infection, usually occurring in individuals under the age of 3 years or over the age of 50 years. it may occur at any age in individuals with immunologic deficiency syndromes. clinical manifestations include fever, altered mentation, headache, meningeal signs, focal neurologic signs, and seizures. (from medicine 1998 sep;77(5):313-36)
  • 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)
  • 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)
  • Meningitis, Viral

    viral infections of the leptomeninges and subarachnoid space. togaviridae infections; flaviviridae infections; rubella; bunyaviridae infections; orbivirus infections; picornaviridae infections; orthomyxoviridae infections; rhabdoviridae infections; arenaviridae infections; herpesviridae infections; adenoviridae infections; jc virus infections; and retroviridae infections may cause this form of meningitis. clinical manifestations include fever, headache, neck pain, vomiting, photophobia, and signs of meningeal irritation. (from joynt, clinical neurology, 1996, ch26, pp1-3)
  • Tuberculosis, Meningeal

    a form of bacterial meningitis caused by mycobacterium tuberculosis or rarely mycobacterium bovis. the organism seeds the meninges and forms microtuberculomas which subsequently rupture. the clinical course tends to be subacute, with progressions occurring over a period of several days or longer. headache and meningeal irritation may be followed by seizures, cranial neuropathies, focal neurologic deficits, somnolence, and eventually coma. the illness may occur in immunocompetent individuals or as an opportunistic infection in the acquired immunodeficiency syndrome and other immunodeficiency syndromes. (from adams et al., principles of neurology, 6th ed, pp717-9)
  • Subdural Effusion

    leakage and accumulation of cerebrospinal fluid in the subdural space which may be associated with an infectious process; craniocerebral trauma; brain neoplasms; intracranial hypotension; and other conditions.
  • Arachnoiditis

    acute or chronic inflammation of the arachnoid membrane of the meninges most often involving the spinal cord or base of the brain. this term generally refers to a persistent inflammatory process characterized by thickening of the arachnoid membrane and dural adhesions. associated conditions include prior surgery, infections, trauma, subarachnoid hemorrhage, and chemical irritation. clinical features vary with the site of inflammation, but include cranial neuropathies, radiculopathies, and myelopathies. (from joynt, clinical neurology, 1997, ch48, p25)
  • Opportunistic Infections

    an infection caused by an organism which becomes pathogenic under certain conditions, e.g., during immunosuppression.
  • Spinal Arachnoiditis

    a chronic adhesive arachnoiditis in the spinal arachnoid, with root and spinal cord symptoms similar to those caused by pressure from a tumor.
  • Arachnoiditis

    inflammation of the arachnoid membrane and adjacent subarachnoid space.
  • Arachnoiditis, CTCAE|Arachnoiditis|Arachnoiditis

    a disorder characterized by inflammation of the arachnoid membrane and adjacent subarachnoid space.
  • Grade 1 Arachnoiditis, CTCAE|Grade 1 Arachnoiditis

    mild symptoms
  • Grade 2 Arachnoiditis, CTCAE|Grade 2 Arachnoiditis

    moderate symptoms; limiting instrumental adl
  • Grade 3 Arachnoiditis, CTCAE|Grade 3 Arachnoiditis

    severe symptoms; limiting self care adl
  • Grade 4 Arachnoiditis, CTCAE|Grade 4 Arachnoiditis

    life-threatening consequences; urgent intervention indicated
  • Grade 5 Arachnoiditis, CTCAE|Grade 5 Arachnoiditis


Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.

Inclusion Terms

Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
  • Arachnoiditis (spinal) NOS

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Convert G03.9 to ICD-9-CM

  • ICD-9-CM Code: 322.9 - Meningitis NOS

Patient Education


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. It usually starts with bacteria that cause a cold-like infection. It can cause stroke, hearing loss, and brain damage. It can also harm other organs. Pneumococcal infections and meningococcal infections are the most common causes of bacterial meningitis.

Anyone can get meningitis, but it is more common in people with weak immune systems. Meningitis can get serious very quickly. You should get medical care right away if you have:

  • A sudden high fever
  • A severe headache
  • A stiff neck
  • Nausea or vomiting

Early treatment can help prevent serious problems, including death. Tests to diagnose meningitis include blood tests, imaging tests, and a spinal tap to test cerebrospinal fluid. Antibiotics can treat bacterial meningitis. Antiviral medicines may help some types of viral meningitis. Other medicines can help treat symptoms.

There are vaccines to prevent some of the bacterial infections that cause meningitis.

NIH: National Institute of Neurological Disorders and Stroke

[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.


[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.