2026 ICD-10-CM Diagnosis Code G99.0Autonomic neuropathy in diseases classified elsewhere
ICD-10-CM Codes›G00–G99›G89-G99›G99
- Billable — Valid for Submission
- Chronic Condition
G99.0 is a billable ICD-10-CM diagnosis code for autonomic neuropathy in diseases classified elsewhere. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is a manifestation code that cannot be reported as the principal diagnosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other nervous system disorders (often hereditary or degenerative).
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for G99.0.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Autoimmune disorder of autonomic nerve
- Autoimmune disorder of autonomic nervous system
- Autoimmune ganglionopathy
- Autonomic neuropathy due to Allgrove syndrome
- Autonomic neuropathy due to endocrine disease
- Autonomic neuropathy due to Fabry disease
- Autonomic neuropathy due to medication induced hypoglycemia
- Autonomic neuropathy due to metabolic disease
- Autonomic neuropathy due to multiple endocrine neoplasia type 2b
- Autonomic neuropathy due to Refsum Disease
- Autonomic neuropathy due to Tangier disease
- Neuropathy associated with hypoglycemia
- Nutritional autonomic neuropathy
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Code First
Type 1 Excludes
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Autonomic Nervous System Disorders
Your autonomic nervous system is the part of your nervous system that controls involuntary actions, such as the beating of your heart and the widening or narrowing of your blood vessels. When something goes wrong in this system, it can cause serious problems, including:
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert G99.0 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About G99.0Overview
Is G99.0 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report autonomic neuropathy in diseases classified elsewhere on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Can G99.0 be a principal diagnosis?
No. This is a manifestation code: autonomic neuropathy in diseases classified elsewhere describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.
What is the ICD-9 equivalent of G99.0?
Under the General Equivalence Mappings, autonomic neuropathy in diseases classified elsewhere converts to ICD-9-CM 337.1 (aut neuropthy in oth dis). The mapping is a direct match.
Footnotes
[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:
- The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
- The condition places limitations on self-care, independent living, and social interactions.
