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Compare/G91 vs Q05

G91 vs Q05

G91 (Hydrocephalus) compared with Q05 (Spina bifida), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.

Can these codes be reported together?

No — do not report together. G91 carries an Excludes1 note covering Q05: “spina bifida with hydrocephalus (Q05.-)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Side by side

G91HydrocephalusQ05Spina bifida
Billing statusNon-billable header

Report instead: G91.0, G91.1, G91.2, G91.3, G91.4

Non-billable header

Report instead: Q05.0, Q05.1, Q05.2, Q05.3, Q05.4

ClassificationG00-G99 — Diseases of the Nervous System (G00-G99)Q00-Q99 — Congenital Malformations, Deformations and Chromosomal Abnormalities (Q00-Q99)
DefinitionHydrocephalus is a non-billable ICD-10-CM category code (G91).Spina bifida is a non-billable ICD-10-CM category code (Q05).
Includes
acquired hydrocephalus
hydromeningocele (spinal)
meningocele (spinal)
meningomyelocele
myelocele
Use additional code—
code for any associated paraplegia (paraparesis) (G82.2-)
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Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources