ICD-10 Code for Encephalopathy
Also indexed as (acute)
The ICD-10-CM code for encephalopathy is G93.40 — Encephalopathy, unspecified. This is the code the Alphabetic Index gives for encephalopathy with no further qualifier, valid for FY2027 (October 1, 2026 – September 30, 2027).
G93.40 is billable but unspecified. If the documentation names a type, site or cause, one of the more specific codes below is likely expected.
Which encephalopathy code should you use?
The Alphabetic Index lists 44 codes under Encephalopathy. Which one applies depends on the qualifier documented in the record — the type, site, cause, or associated condition. Find the qualifier below, then verify the code in the Tabular List before using it.
By type
| acute necrotizing hemorrhagic | G04.30 | Acute necrotizing hemorrhagic encephalopathy, unspecified | |
| alcoholic | G31.2 | Degeneration of nervous system due to alcohol | |
| arteriosclerotic | I67.2 | Cerebral atherosclerosis | |
| centrolobar progressive | G37.0 | Diffuse sclerosis of central nervous system | |
| congenital | Q07.9 | Congenital malformation of nervous system, unspecified | |
| degenerative, in specified disease NEC | G32.89 | Other specified degenerative disorders of nervous system in diseases classified elsewhere | |
| demyelinating callosal | G37.1 | Central demyelination of corpus callosum | |
| developmental and epileptic | G93.45 | Developmental and epileptic encephalopathy | |
| early infantile epileptic | G93.45 | Developmental and epileptic encephalopathy | |
| FOXG1-related | QA0.0151 | FOXG1 syndrome | |
| hepatic | K76.82 | Hepatic encephalopathy | |
| hyperbilirubinemic, newborn | P57.9 | Kernicterus, unspecified | |
| hypertensive | I67.4 | Hypertensive encephalopathy | |
| hypoglycemic | E16.2 | Hypoglycemia, unspecified | |
| hypoxic ischemic | P91.60 | Hypoxic ischemic encephalopathy [HIE], unspecified | |
| metabolic | G93.41 | Metabolic encephalopathy | |
| necrotizing, subacute | G31.82 | Leigh's disease | |
| neonatal | P91.819 | Neonatal encephalopathy, unspecified | |
| pellagrous | E52 | Niacin deficiency [pellagra] | |
| portal-systemic | K76.82 | Hepatic encephalopathy | |
| postcontusional | F07.81 | Postconcussional syndrome | |
| posthypoglycemic | E16.1 | Other hypoglycemia | |
| postradiation | G93.89 | Other specified disorders of brain | |
| septic | G93.41 | Metabolic encephalopathy | |
| specified NEC | G93.49 | Other encephalopathy | |
| spongiform, subacute | A81.09 | Other Creutzfeldt-Jakob disease | |
| toxic | G92.9 | Unspecified toxic encephalopathy | |
| traumatic | F07.81 | Postconcussional syndrome | |
| vitamin B deficiency NEC | E53.9 | Vitamin B deficiency, unspecified | |
| Wernicke's | E51.2 | Wernicke's encephalopathy |
Encephalopathy acute necrotizing hemorrhagic
Encephalopathy due to
| drugs | G92.8 | Other toxic encephalopathy |
Encephalopathy hyperbilirubinemic, newborn
| due to isoimmunization | P57.0 | Kernicterus due to isoimmunization |
Encephalopathy hypoxic ischemic
Encephalopathy in
| birth injury | P11.1 | Other specified brain damage due to birth injury | |
| hyperinsulinism | E16.1 | Other hypoglycemia | |
| lack of vitamin | E56.9 | Vitamin deficiency, unspecified | |
| neoplastic disease | D49.9 | Neoplasm of unspecified behavior of unspecified site | |
| serum | T80.69 | Other serum reaction due to other serum | not billable |
| syphilis | A52.17 | General paresis | |
| trauma | F07.81 | Postconcussional syndrome | |
| vaccination | G04.02 | Postimmunization acute disseminated encephalitis, myelitis and encephalomyelitis |
Encephalopathy metabolic
Encephalopathy neonatal
| in diseases classified elsewhere | P91.811 | Neonatal encephalopathy in diseases classified elsewhere |
Encephalopathy toxic
| metabolic | G92.8 | Other toxic encephalopathy |
Encephalopathy vitamin B deficiency NEC
| vitamin B1 | E51.2 | Wernicke's encephalopathy |
Index terms and codes are reproduced from the official ICD-10-CM FY2027 release. The Alphabetic Index is a finding aid — a code must always be verified in the Tabular List before it is reported. Data sources