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G90.1

G90.1Familial dysautonomia [Riley-Day]

Billable / specific codeICD-10-CM

G90.1 is a billable, specific ICD-10-CM code for familial dysautonomia [riley-day]. It is valid for submission on a claim.

Other codes that can never be billed with G90.1

These codes carry an Excludes1 note pointing at G90.1. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading G90.1 alone.

  • Q85Phakomatoses, not elsewhere classified

Risk adjustment

G90.1 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:

  • HCC 182 Spinal Cord Disorders/Injuries0.478 RAF

Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score.

Medicare coverage

G90.1 is named in 5 Medicare coverage policies 5 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A54111Billing and Coding: Speech Language Pathology (SLP) Services: Communication Disorders
  • A56612Billing and Coding: CT of the Head
  • A56619Billing and Coding: Nerve Conduction Studies and Electromyography
  • A57204Billing and Coding: MRI and CT Scans of the Head and Neck

How G90.1 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to G90.1.

  • Dysautonomia(familial)
  • Riley-Day syndrome

Related codes at this level

Codes that share G90. If G90.1 is not quite right, the correct code is usually one of these.

Questions about G90.1

Is G90.1 a billable ICD-10-CM code?
Yes. G90.1 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does G90.1 sit in the tabular list?
Diseases of the nervous system (G00-G99), in the block Other disorders of the nervous system (G89-G99).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.