FY2027 ICD-10-CM reference
G40.4: Other generalized epilepsy and epileptic syndromes
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is Other generalized epilepsy and epileptic syndromes. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Nonbillable heading. Verified against the official FY2027 order file.
More specific FY2027 codes
- G40.40: Other generalized epilepsy and epileptic syndromes, not intractableNonbillable heading
- G40.41: Other generalized epilepsy and epileptic syndromes, intractableNonbillable heading
- G40.42: Cyclin-Dependent Kinase-Like 5 Deficiency DisorderBillable code
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Excludes2
certain conditions originating in the perinatal period (P04-P96)
Source: G00-G99 (chapter, inherited).
Excludes2
certain infectious and parasitic diseases (A00-B99)
Source: G00-G99 (chapter, inherited).
Excludes2
complications of pregnancy, childbirth and the puerperium (O00-O9A)
Source: G00-G99 (chapter, inherited).
Excludes2
congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
Source: G00-G99 (chapter, inherited).
Excludes2
endocrine, nutritional and metabolic diseases (E00-E88)
Source: G00-G99 (chapter, inherited).
Excludes2
injury, poisoning and certain other consequences of external causes (S00-T88)
Source: G00-G99 (chapter, inherited).
Excludes2
neoplasms (C00-D49)
Source: G00-G99 (chapter, inherited).
Excludes2
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Source: G00-G99 (chapter, inherited).
Instructional note
the following terms are to be considered equivalent to intractable: pharmacoresistant (pharmacologically resistant), treatment resistant, refractory (medically) and poorly controlled
Source: G40 (category, inherited).
Excludes1
conversion disorder with seizures (F44.5)
Source: G40 (category, inherited).
Excludes1
convulsions NOS (R56.9)
Source: G40 (category, inherited).
Excludes1
post traumatic seizures (R56.1)
Source: G40 (category, inherited).
Excludes1
seizure (convulsive) NOS (R56.9)
Source: G40 (category, inherited).
Excludes1
seizure of newborn (P90)
Source: G40 (category, inherited).
Excludes2
hippocampal sclerosis (G93.81)
Source: G40 (category, inherited).
Excludes2
mesial temporal sclerosis (G93.81)
Source: G40 (category, inherited).
Excludes2
temporal sclerosis (G93.81)
Source: G40 (category, inherited).
Excludes2
Todd's paralysis (G83.84)
Source: G40 (category, inherited).
Instructional note
Epilepsy with grand mal seizures on awakening
Source: G40.4 (self, direct).
Instructional note
Epilepsy with myoclonic absences
Source: G40.4 (self, direct).
Instructional note
Epilepsy with myoclonic-astatic seizures
Source: G40.4 (self, direct).
Instructional note
Grand mal seizure NOS
Source: G40.4 (self, direct).
Instructional note
Nonspecific atonic epileptic seizures
Source: G40.4 (self, direct).
Instructional note
Nonspecific clonic epileptic seizures
Source: G40.4 (self, direct).
Instructional note
Nonspecific myoclonic epileptic seizures
Source: G40.4 (self, direct).
Instructional note
Nonspecific tonic epileptic seizures
Source: G40.4 (self, direct).
Instructional note
Nonspecific tonic-clonic epileptic seizures
Source: G40.4 (self, direct).
Instructional note
Symptomatic early myoclonic encephalopathy
Source: G40.4 (self, direct).
Compare the FY2027 additions, removals and billable-status changes
What does G40.4 mean in FY2027?
The official ICD-10-CM descriptor is Other generalized epilepsy and epileptic syndromes. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Is G40.4 billable in FY2027?
The FY2027 order file marks G40.4 as a nonbillable heading. Select a complete billable child code.
Does G40.4 map to an HCC?
Risk-model mapping is not applicable to this nonbillable heading. Check a complete billable child code.
Source: CMS FY2027 ICD-10-CM order file. Read the FY2027 Official Guidelines.
Review the FY2026 April edition