G40.9
Epilepsy, unspecified
Not billable — category only FY2026 2025-10-01 → 2026-09-30
This is the unspecified option. 10 more
specific codes sit alongside it. Worth
checking whether the documentation supports one of them.
Exclusions 17 never code together
G40code
Excludes1
G00-G99chapter
Excludes2
- certain conditions originating in the perinatal period (P04-P96)P04-P96
- certain infectious and parasitic diseases (A00-B99)A00-B99
- complications of pregnancy, childbirth and the puerperium (O00-O9A)O00-O9A
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Q00-Q99
- endocrine, nutritional and metabolic diseases (E00-E88)E00-E88
- injury, poisoning and certain other consequences of external causes (S00-T88)S00-T88
- neoplasms (C00-D49)C00-D49
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)R00-R94
Excludes1 — never code together. The excluded condition and this one are mutually exclusive.
Excludes2 — not included here, but the patient may have both. Code both when documented.
Instructional notes 1
G40code
Notes
- the following terms are to be considered equivalent to intractable: pharmacoresistant (pharmacologically resistant), treatment resistant, refractory (medically) and poorly controlled
Index entries leading here filed at null
No alphabetic index entry points at this code.
Alongside this code 10 same parent — G40
G40.0 Local-rel (focal) idio epilepsy w seizures of loc onset category G40.1 Local-rel (focal) symptc epilepsy w simple partial seizures category G40.2 Local-rel (focal) symptc epilepsy w complex partial seizures category G40.3 Generalized idiopathic epilepsy and epileptic syndromes category G40.A Absence epileptic syndrome category G40.B Juvenile myoclonic epilepsy [impulsive petit mal] category G40.C Lafora progressive myoclonus epilepsy category G40.4 Other generalized epilepsy and epileptic syndromes category G40.5 Epileptic seizures related to external causes category G40.8 Other epilepsy and recurrent seizures category
Subordinate codes 2
Medications 5
64 Epilepsy drugs 25 Epilepsy, Generalized drugs 9 Epilepsy, Absence drugs 13 Epilepsy, Tonic-Clonic drugs 8 Epilepsy, Complex Partial drugs
MED-RT files conditions by MeSH, which carves the world differently from ICD-10. These are name matches on this code's description, offered as candidates — not as an assertion that they are this code.
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.