G90.8Other disorders of autonomic nervous system

G90.8 is the ICD-10-CM diagnosis code for other disorders of autonomic nervous system. It belongs to category G90 (disorders of autonomic nervous system), block G89-G99 (other disorders of the nervous system) and chapter 6 (diseases of the nervous system). It is a header code, so it can't be reported by itself; one of its 2 subcodes must be used instead.

Within G90, choose G90.8 (Other disorders of autonomic nervous system) only when documentation doesn't support a more specific option: idiopathic peripheral autonomic neuropathy (G90.0), familial dysautonomia [Riley-Day] (G90.1), Horner's syndrome (G90.2), Multi-system degeneration of the autonomic nervous system (G90.3), autonomic dysreflexia (G90.4), complex regional pain syndrome I (CRPS I) (G90.5), disorder of the autonomic nervous system, unspecified (G90.9), postural orthostatic tachycardia syndrome [POTS] (G90.A) and 1 more.

To report this condition, pick the subcode that matches the documentation: G90.81 (syndrome) and G90.89 (system).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015, and changed in FY2025 (expanded into subcodes).

Before ICD-10, this condition was coded in ICD-9-CM as 337.9 (unspecified disorder of autonomic nervous system).