G11.9
BillableHereditary ataxia, unspecified
HCC Category Mapping
V28HCC 200 — Cerebellar Ataxia and Other Degenerative Diseases of Nervous System
0.262V24HCC 72 — Spinal Cord Disorders/Injuries
0.464ESRDHCC 72 — Spinal Cord Disorders/Injuries
0.000What This Code Means
An inherited disorder affecting coordination and balance when the specific type of hereditary ataxia cannot be determined or is not specified.
Coding Tips
- •This is a default code used when the specific hereditary ataxia type is unknown; query the provider for more specific diagnosis if available
- •Avoid using this code if any specific ataxia subtype can be identified from documentation
Clinical Significance
Hereditary ataxia, unspecified is used when a patient has a confirmed hereditary coordination disorder but the specific subtype has not been determined. While this captures disease burden, it represents a missed opportunity for specificity and may indicate incomplete diagnostic workup. Coders should query providers whenever possible to obtain a more specific diagnosis.
Documentation Requirements
- ✓Documentation confirming the ataxia is hereditary in nature
- ✓Family history of ataxia or documented genetic basis
- ✓Neurological examination findings consistent with cerebellar dysfunction
- ✓Explanation of why specific subtype cannot be determined (pending testing, inconclusive results)
- ✓Current functional status and care plan
- ✓Any prior or planned genetic testing
Commonly Confused Codes
R27.0 — Ataxia, unspecified: for ataxia without established hereditary diagnosisG11.8 — Other hereditary ataxias: use when a specific type is known but lacks its own codeG11.10 — Early-onset cerebellar ataxia, unspecified: more specific if onset age is knownG11.2 — Late-onset cerebellar ataxia: more specific if adult onset is documented