G90 — Disorders of autonomic nervous system
G90 is a non-billable header ICD-10-CM code for disorders of autonomic nervous system. It cannot be billed on its own: choose one of the more specific child codes below.
Excludes1 — never code together
These conditions cannot occur together. Billing both on the same encounter is a denial.
- dysfunction of the autonomic nervous system due to alcohol (G31.2)
Other codes that can never be billed with G90
These codes carry an Excludes1 note pointing at G90. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading G90 alone.
Risk adjustment
G90 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Code history
G90 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.
Code to one of these instead G90
10 child codes. Green means billable.
- G90.0Idiopathic peripheral autonomic neuropathy
- G90.1Familial dysautonomia [Riley-Day]
- G90.2Horner's syndrome
- G90.3Multi-system degeneration of the autonomic nervous system
- G90.4Autonomic dysreflexia
- G90.5Complex regional pain syndrome I (CRPS I)
- G90.8Other disorders of autonomic nervous system
- G90.9Disorder of the autonomic nervous system, unspecified
- G90.APostural orthostatic tachycardia syndrome [POTS]
- G90.BLMNB1-related autosomal dominant leukodystrophy
Questions about G90
- Is G90 a billable ICD-10-CM code?
- No. G90 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
- Where does G90 sit in the tabular list?
- Diseases of the nervous system (G00-G99), in the block Other disorders of the nervous system (G89-G99).
- What cannot be coded together with G90?
- G90 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter.