ICD-10-CM 2027
ICD-10 code for Seizure
Confirmed by the official ICD-10-CM index entry “seizure (s)”. Page updated September 29, 2026.
About coding Seizure
The ICD-10-CM code for Seizure is R56.9 (Unspecified convulsions). The official index lists 61 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on R56.9.
It is also searched as convulsions.
Within R56, choose R56.9 (Unspecified convulsions) only when documentation doesn't support a more specific option: febrile convulsions (R56.0) and post traumatic seizures (R56.1).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 100 (Seizures with MCC, relative weight 1.9233), DRG 101 (Seizures without MCC, relative weight 0.8952), DRG 791 (Prematurity with Major Problems, relative weight 4.1075) and DRG 793 (Full Term Neonate with Major Problems, relative weight 4.2195), in MDC 01 (Diseases and Disorders of the Nervous System) and MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Related Seizure codes
- G40.001 Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, with status epilepticus
- G40.009 Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, without status epilepticus
- G40.011 Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, with status epilepticus
- G40.019 Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, without status epilepticus
- G40.101 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, with status epilepticus
- G40.109 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, without status epilepticus
- G40.111 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable, with status epilepticus
- G40.119 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable, without status epilepticus
- G40.201 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, with status epilepticus
- G40.209 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, without status epilepticus
- G40.211 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, with status epilepticus
- G40.219 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, without status epilepticus
- G40.301 Generalized idiopathic epilepsy and epileptic syndromes, not intractable, with status epilepticus
- G40.309 Generalized idiopathic epilepsy and epileptic syndromes, not intractable, without status epilepticus
- G40.311 Generalized idiopathic epilepsy and epileptic syndromes, intractable, with status epilepticus
- G40.319 Generalized idiopathic epilepsy and epileptic syndromes, intractable, without status epilepticus
- G40.401 Other generalized epilepsy and epileptic syndromes, not intractable, with status epilepticus
- G40.409 Other generalized epilepsy and epileptic syndromes, not intractable, without status epilepticus
- G40.411 Other generalized epilepsy and epileptic syndromes, intractable, with status epilepticus
- G40.419 Other generalized epilepsy and epileptic syndromes, intractable, without status epilepticus
- G40.42 Cyclin-Dependent Kinase-Like 5 Deficiency Disorder
- G40.501 Epileptic seizures related to external causes, not intractable, with status epilepticus
- G40.509 Epileptic seizures related to external causes, not intractable, without status epilepticus
- G40.801 Other epilepsy, not intractable, with status epilepticus
- G40.802 Other epilepsy, not intractable, without status epilepticus
- G40.803 Other epilepsy, intractable, with status epilepticus
- G40.804 Other epilepsy, intractable, without status epilepticus
- G40.811 Lennox-Gastaut syndrome, not intractable, with status epilepticus
- G40.812 Lennox-Gastaut syndrome, not intractable, without status epilepticus
- G40.813 Lennox-Gastaut syndrome, intractable, with status epilepticus
- G40.814 Lennox-Gastaut syndrome, intractable, without status epilepticus
- G40.821 Epileptic spasms, not intractable, with status epilepticus
- G40.822 Epileptic spasms, not intractable, without status epilepticus
- G40.823 Epileptic spasms, intractable, with status epilepticus
- G40.824 Epileptic spasms, intractable, without status epilepticus
- G40.833 Dravet syndrome, intractable, with status epilepticus
- G40.834 Dravet syndrome, intractable, without status epilepticus
- G40.841 KCNQ2-related epilepsy, not intractable, with status epilepticus
- G40.842 KCNQ2-related epilepsy, not intractable, without status epilepticus
- G40.843 KCNQ2-related epilepsy, intractable, with status epilepticus
- G40.844 KCNQ2-related epilepsy, intractable, without status epilepticus
- G40.89 Other seizures
- G40.901 Epilepsy, unspecified, not intractable, with status epilepticus
- G40.909 Epilepsy, unspecified, not intractable, without status epilepticus
- G40.911 Epilepsy, unspecified, intractable, with status epilepticus
- G40.919 Epilepsy, unspecified, intractable, without status epilepticus
- G40.A01 Absence epileptic syndrome, not intractable, with status epilepticus
- G40.A09 Absence epileptic syndrome, not intractable, without status epilepticus
- G40.A11 Absence epileptic syndrome, intractable, with status epilepticus
- G40.A19 Absence epileptic syndrome, intractable, without status epilepticus
- G40.B01 Juvenile myoclonic epilepsy, not intractable, with status epilepticus
- G40.B09 Juvenile myoclonic epilepsy, not intractable, without status epilepticus
- G40.B11 Juvenile myoclonic epilepsy, intractable, with status epilepticus
- G40.B19 Juvenile myoclonic epilepsy, intractable, without status epilepticus
- G40.C01 Lafora progressive myoclonus epilepsy, not intractable, with status epilepticus
- G40.C09 Lafora progressive myoclonus epilepsy, not intractable, without status epilepticus
- G40.C11 Lafora progressive myoclonus epilepsy, intractable, with status epilepticus
- G40.C19 Lafora progressive myoclonus epilepsy, intractable, without status epilepticus
- R56.00 Simple febrile convulsions
- R56.01 Complex febrile convulsions
- R56.1 Post traumatic seizures
Common questions about Seizure ICD-10 codes
What is the ICD-10 code for Seizure?
- R56.9 — Unspecified convulsions. More specific codes apply when the documentation supports them: G40.001, G40.009, G40.011, G40.019 and others below.
What is the ICD-10 code for localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, with status epilepticus?
- G40.001 — Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, with status epilepticus.
What is the ICD-10 code for localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, without status epilepticus?
- G40.009 — Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, without status epilepticus.
What is the ICD-10 code for localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, with status epilepticus?
- G40.011 — Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, with status epilepticus.
What is the ICD-10 code for localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, without status epilepticus?
- G40.019 — Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, without status epilepticus.
What is the ICD-10 code for localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, with status epilepticus?
- G40.101 — Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, with status epilepticus.
What is the ICD-10 code for localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, without status epilepticus?
- G40.109 — Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, without status epilepticus.
Is R56.9 billable?
- Yes. R56.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can R56.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict R56.9 as a principal diagnosis.
Is R56.9 a CC or MCC?
- No. R56.9 is neither a CC nor an MCC under MS-DRG v44.0.