2026 ICD-10-CM Diagnosis Code R29.1Meningismus

ICD-10-CM Codes›R00–R99›R25-R29›R29

ICD-10-CM R29.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R29.1 is a billable ICD-10-CM diagnosis code for meningismus. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nervous system signs and symptoms.

Code Identity

ICD-10-CM Code
R29.1
Billable Status
Yes — Valid for Submission
Code Describes
Meningismus
Short Description
Meningismus
Same as the full description in the CMS dataset.
Parent Code
R29
Other symptoms and signs involving the nervous and musculoskeletal systems

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR25-R29Symptoms and signs involving the nervous and musculoskeletal systems
CategoryR29Other symptoms and signs involving the nervous and musculoskeletal systems
This CodeR29.1Meningismus

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Decreased flexion
  • Meningeal irritation
  • Meningism
  • Meningism present
  • Nuchal rigidity
  • Nuchal rigidity due to meningitis
  • Nuchal rigidity due to subarachnoid hemorrhage

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Disease, diseased
      • Dupré's (meningism)
    • Dupré's disease(meningism)
    • Meningismus(infectional) (pneumococcal)
    • Meningismus(infectional) (pneumococcal)
      • due to serum or vaccine
    • Rigid, rigidity
      • nuchal
    • Syndrome
      • Dupré's (meningism)

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR SYM010
Nervous system signs and symptoms
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • 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)

Patient EducationClinical

Neurologic Diseases

The brain, spinal cord, and nerves make up the nervous system. Together they control all the workings of the body. When something goes wrong with a part of your nervous system, you can have trouble moving, speaking, swallowing, breathing, or learning. You can also have problems with your memory, senses, or mood.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert R29.1 to ICD-9-CMHistory

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

ICD-9-CM
781.6 Meningismus
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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About R29.1Overview

Is R29.1 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report meningismus on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can R29.1 be a principal diagnosis?

Use it with care. This is a symptom code, so once a definitive diagnosis explaining the meningismus is established, that condition takes the principal position instead.

What is the ICD-9 equivalent of R29.1?

Under the General Equivalence Mappings, meningismus converts to ICD-9-CM 781.6 (meningismus). The mapping is a direct match.

Footnotes

[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.