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H55.01

H55.01Congenital nystagmus

Billable / specific codeICD-10-CM

H55.01 is a billable, specific ICD-10-CM code for congenital nystagmus. It is valid for submission on a claim.

Other codes that can never be billed with H55.01

These codes carry an Excludes1 note pointing at H55.01. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading H55.01 alone.

  • Q15Other congenital malformations of eye

Risk adjustment

H55.01 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.

Medicare coverage

H55.01 is named in 6 Medicare coverage policies 6 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A56551Billing and Coding: Visual Fields Testing
  • A56729Billing and Coding: Magnetic Resonance Imaging of the Head and Neck
  • A56799Billing and Coding: Visual Fields Testing
  • A57204Billing and Coding: MRI and CT Scans of the Head and Neck

How H55.01 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 H55.01.

  • Nystagmuscongenital

Related codes at this level

Codes that share H55.0. If H55.01 is not quite right, the correct code is usually one of these.

Questions about H55.01

Is H55.01 a billable ICD-10-CM code?
Yes. H55.01 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does H55.01 sit in the tabular list?
Diseases of the eye and adnexa (H00-H59), in the block Other disorders of eye and adnexa (H55-H57).
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.