MCMedicalCodingSoftware
G91.3

G91.3: Post-traumatic hydrocephalus, unspecified

Billable / specific codeICD-10-CM

G91.3 is a billable, specific ICD-10-CM code for post-traumatic hydrocephalus, unspecified. It is valid for submission on a claim.

Check G91.3 with the rest of the claim: free scrubber

Excludes1 inherited from the categories above G91.3

A category’s note binds every code beneath it.

Written on G91: Hydrocephalus

  • Arnold-Chiari syndrome with hydrocephalus (Q07.-)
  • congenital hydrocephalus (Q03.-)
  • spina bifida with hydrocephalus (Q05.-)

Other codes that can never be billed with G91.3

Their own Excludes1 notes name this code, so the conflict is not listed above.

  • Q03Congenital hydrocephalus

Risk adjustment

G91.3 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:

  • HCC 127 Dementia, Mild or Unspecified0.341 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. Look up the whole chart to see which of its HCCs the hierarchy would zero.

Medicare coverage

G91.3 is named in 4 Medicare coverage policies: 4 listing it as supporting medical necessity. Which one applies depends on your Medicare contractor.

  • A54111Billing and Coding: Speech Language Pathology (SLP) Services: Communication Disorders
  • A56612Billing and Coding: CT of the Head
  • A57204Billing and Coding: MRI and CT Scans of the Head and Neck
  • A57780Billing and Coding: Psychological and Neuropsychological Tests

Alphabetic index entries that lead here

  • Hydrocephalus›post-traumatic NEC
  • Hydrocephalus›secondary›post-traumatic

Code history

Unchanged in every release from FY2024 to FY2027.

Other codes under G91

ICD-10-CMFY2027· effective October 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.