G89-G99 — Other disorders of the nervous system
ICD-10-CM codes G89-G99 cover other disorders of the nervous system, within diseases of the nervous system. The block holds 146 codes across 11 categories, of which 112 are billable and 34 are header codes that cannot be submitted on a claim.
Risk adjustment in G89-G99
0 codes in this block map to a CMS-HCC, which means the diagnosis carries a risk-adjustment payment when it is documented and coded. Under-coding here is money left on the table; over-coding here is what audits are for.
- HCC 182 Spinal Cord Disorders/Injuries
- HCC 127 Dementia, Mild or Unspecified
- HCC 200 Friedreich and Other Hereditary Ataxias; Huntington Disease
- HCC 202 Coma, Brain Compression/Anoxic Damage
- HCC 199 Parkinson and Other Degenerative Disease of Basal Ganglia
- HCC 201 Seizure Disorders and Convulsions
What else to watch in G89-G99
- 4 codes are laterality-specific. They come in left and right pairs, and the pair is mutually exclusive on a single site: coding both without a bilateral code is a contradiction a scrubber should catch before the payer does.
- 110 codes are named in Medicare coverage policies. An LCD or NCD lists them as supporting medical necessity, or explicitly as not supporting it. Which applies depends on the MAC for your state.
Categories in G89-G99
- G89Pain, not elsewhere classified
- G90Disorders of autonomic nervous system
- G91Hydrocephalus
- G92Toxic encephalopathy
- G93Other disorders of brain
- G94Other disorders of brain in diseases classified elsewhere
- G95Other and unspecified diseases of spinal cord
- G96Other disorders of central nervous system
- G97Intraoperative and postprocedural complications and disorders of nervous system, not elsewhere classified
- G98Other disorders of nervous system not elsewhere classified
- G99Other disorders of nervous system in diseases classified elsewhere