G91.4 vs G94
G91.4 and G94 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on G94
hydrocephalus in diseases classified elsewhere (G91.4)
G91.4
Hydrocephalus in diseases classified elsewhere
Billable
- Chapter 6
- Diseases of the nervous system
- Section
- G89-G99
Indexed under
- Hydrocephalus › secondary (acquired) (external) (internal) (malignant) (recurrent)
- Hydrocephalus › in › infectious disease NEC (acquired) (external) (internal) (malignant) (recurrent)
- Hydrocephalus › in › neoplastic disease NEC (acquired) (external) (internal) (malignant) (recurrent)
- Hydrocephalus › in › parasitic disease (acquired) (external) (internal) (malignant) (recurrent)
G94
Other disorders of brain in diseases classified elsewhere
Billable
- Chapter 6
- Diseases of the nervous system
- Section
- G89-G99
Indexed under
- Encephalopathy › posthypoglycemic (acute)
- Epilepsy, epileptic, epilepsia › parasitic NOS (attack) (cerebral) (convulsion) (fit) (seizure)
- Malaria, malarial › cerebral (fever)
- Typhus › brain (fever)
- Typhus › cerebral (fever)
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027