2025 ICD-10-CM code G99.8
(Active) Effective Date: N/A Diseases of the nervous system - Other disorders of the nervous system 6 Feed
Other specified disorders of the nervous system in diseases classified elsewhere. Code first the underlying disorder.
Medical necessity must be established by demonstrating a direct causal link between the underlying disease and the specified nervous system disorder. Documentation should support the need for treatment and/or management of the neurological symptoms.
Clinical responsibility varies depending on the underlying disease or disorder. General symptoms may include tingling, numbness, and weakness in the extremities, and changes in cognitive function, personality, or behavior. Diagnosis is based on medical history, signs and symptoms, neurological evaluation, and diagnostic studies like blood tests, MRI, CT scan, EEG, EMG, or NCV.
In simple words: This code is used for disorders of the nervous system that are caused by another disease.It's important to code the main disease first, and then use this code to show that the nervous system is also affected.
This code represents other specified disorders of the nervous system that occur secondary to an underlying disease or pathological condition and are not represented by another more specific code. It is used when the nervous system disorder is a component of other diseases classified elsewhere. The primary disease should always be coded first.See official guidelines for included and excluded underlying disorders.
Example 1: A patient with diabetes (E11.9) experiences peripheral neuropathy (G99.8) due to the diabetes. Diabetes is coded first, followed by G99.8., A patient with amyloidosis (E85.9) develops nervous system dysfunction (G99.8). Amyloidosis is coded first, then G99.8., A patient with hypothyroidism (E03.9) experiences neurological symptoms (G99.8) as a result of the thyroid condition. Hypothyroidism is coded first, followed by G99.8.
Documentation should clearly establish the underlying disease or condition causing the nervous system disorder. The medical record should support the diagnosis of the nervous system involvement with relevant signs, symptoms, and diagnostic test results. It should also detail the relationship between the underlying condition and the neurological manifestation.
** Excludes1 nervous system involvement in cysticercosis (B69.0), rubella (B06.-), syphilis (A52.1-). Excludes2 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), 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).
- Payment Status: Active
- Specialties:Neurology, Endocrinology, Internal Medicine, Family Medicine, and other specialties depending on the underlying condition.
- Place of Service:Inpatient Hospital, On Campus-Outpatient Hospital, Off Campus-Outpatient Hospital, Office, Home, and other places of service depending on the underlying condition.