Disorders of autonomic nervous system (G90) ICD-10-CM
The G90 code range covers disorders of autonomic nervous system with 27 ICD-10-CM diagnosis codes. 21 of them are billable and valid for claim submission in fiscal year 2027, and the category headers group them but cannot themselves be billed.
Type 1 Excludes
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.
- dysfunction of the autonomic nervous system due to alcohol G31.2
Codes in the G90 Range 27 codes · 21 billable
- G90 Disorders of autonomic nervous systemNon-billable
- G90.0 Idiopathic peripheral autonomic neuropathyNon-billable
- G90.01 Carotid sinus syncope
- G90.09 Other idiopathic peripheral autonomic neuropathy
- G90.1 Familial dysautonomia [Riley-Day]
- G90.2 Horner's syndrome
- G90.3 Multi-system degeneration of the autonomic nervous system
- G90.4 Autonomic dysreflexia
- G90.5 Complex regional pain syndrome I (CRPS I)Non-billable
- G90.50 Complex regional pain syndrome I, unspecified
- G90.51 Complex regional pain syndrome I of upper limbNon-billable
- G90.511 Complex regional pain syndrome I of right upper limb
- G90.512 Complex regional pain syndrome I of left upper limb
- G90.513 Complex regional pain syndrome I of upper limb, bilateral
- G90.519 Complex regional pain syndrome I of unspecified upper limb
- G90.52 Complex regional pain syndrome I of lower limbNon-billable
- G90.521 Complex regional pain syndrome I of right lower limb
- G90.522 Complex regional pain syndrome I of left lower limb
- G90.523 Complex regional pain syndrome I of lower limb, bilateral
- G90.529 Complex regional pain syndrome I of unspecified lower limb
- G90.59 Complex regional pain syndrome I of other specified site
- G90.8 Other disorders of autonomic nervous systemNon-billable
- G90.81 Serotonin syndrome
- G90.89 Other disorders of autonomic nervous system
- G90.9 Disorder of the autonomic nervous system, unspecified
- G90.A Postural orthostatic tachycardia syndrome [POTS]
- G90.B LMNB1-related autosomal dominant leukodystrophy
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the G90 range.
Autonomic Dysreflexia
A syndrome associated with damage to the spinal cord above the mid thoracic level (see SPINAL CORD INJURIES) characterized by a marked increase in the sympathetic response to minor stimuli such as bladder or rectal distention. Manifestations include HYPERTENSION; TACHYCARDIA (or reflex bradycardia); FEVER; FLUSHING; and HYPERHIDROSIS. Extreme hypertension may be associated with a STROKE. (From Adams et al., Principles of Neurology, 6th ed, pp538 and 1232; J Spinal Cord Med 1997;20(3):355-60)
Autonomic Nervous System Diseases
Diseases of the AUTONOMIC NERVOUS SYSTEM, including sympathetic, parasympathetic, and enteric nervous systems.
Carotid Sinus Syncope
A condition in which neurally mediated syncope occurs due to massage of the carotid body. (ACC/AHA)
Complex Regional Pain Syndrome I
A neurologic condition characterized by burning pain, tenderness, swelling, and changes in the skin color and temperature of a body part or extremity that has no identifiable nerve injury; most pediatric patients present with this form.
Dysautonomia, Familial
An autosomal disorder of the peripheral and autonomic nervous systems limited to individuals of Ashkenazic Jewish descent. Clinical manifestations are present at birth and include diminished lacrimation, defective thermoregulation, orthostatic hypotension (HYPOTENSION, ORTHOSTATIC), fixed pupils, excessive SWEATING, loss of pain and temperature sensation, and absent reflexes. Pathologic features include reduced numbers of small diameter peripheral nerve fibers and autonomic ganglion neurons. (From Adams et al., Principles of Neurology, 6th ed, p1348; Nat Genet 1993;4(2):160-4)
Horner Syndrome
A syndrome associated with defective sympathetic innervation to one side of the face, including the eye. Clinical features include MIOSIS; mild BLEPHAROPTOSIS; and hemifacial ANHIDROSIS (decreased sweating)(see HYPOHIDROSIS). Lesions of the BRAIN STEM; cervical SPINAL CORD; first thoracic nerve root; apex of the LUNG; CAROTID ARTERY; CAVERNOUS SINUS; and apex of the ORBIT may cause this condition. (From Miller et al., Clinical Neuro-Ophthalmology, 4th ed, pp500-11)
Serotonin Syndrome
An adverse drug interaction characterized by altered mental status, autonomic dysfunction, and neuromuscular abnormalities. It is most frequently caused by use of both serotonin reuptake inhibitors and monoamine oxidase inhibitors, leading to excess serotonin availability in the CNS at the serotonin 1A receptor.
Shy-Drager Syndrome
A progressive neurodegenerative condition of the central and autonomic nervous systems characterized by atrophy of the preganglionic lateral horn neurons of the thoracic spinal cord. This disease is generally considered a clinical variant of MULTIPLE SYSTEM ATROPHY. Affected individuals present in the fifth or sixth decade with ORTHOSTASIS and bladder dysfunction; and later develop FECAL INCONTINENCE; anhidrosis; ATAXIA; IMPOTENCE; and alterations of tone suggestive of basal ganglia dysfunction. (From Adams et al., Principles of Neurology, 6th ed, p536)
About the G90 Code Range
These disorders affect the autonomic nervous system. The category includes named conditions such as familial dysautonomia, Horner's syndrome, and complex regional pain syndrome I.
G90.0 groups idiopathic peripheral autonomic neuropathy, with separate subdivisions for carotid sinus syncope and other forms. Other codes identify familial dysautonomia, Horner's syndrome, multi-system degeneration, and autonomic dysreflexia.
G90.5 groups complex regional pain syndrome I by site. Its upper- and lower-limb subdivisions distinguish right, left, both, and unspecified sides. The remaining codes identify serotonin syndrome, postural orthostatic tachycardia syndrome, and LMNB1-related autosomal dominant leukodystrophy, as well as other and unspecified autonomic nervous system disorders.
Questions About This Page
How many billable codes are in the G90 range?
Of the 27 codes in this range, 21 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.
What does the G90 range classify?
The range classifies disorders of autonomic nervous system. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
