DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

Category · FY2027

G40 Epilepsy and recurrent seizures

  • Header · not billable

G40 is not billable. The category heads 58 billable codes in FY2027, grouped under 11 subdivisions.

Index → code

Where it sits

  1. Chapter 6 Diseases of the nervous system (G00-G99)
  2. G40-G47 Episodic and paroxysmal disorders (G40-G47)
  3. G40 Epilepsy and recurrent seizures
Billable codes
58
Subdivisions
11
CC / MCC codes
47 / 3
HCC V28 codes
58
New FY2027
0
Index entries
243

Codes in G40

  1. G40.0
    Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset
    Header
    Inclusion terms 2, Excludes1 1

    Inclusion terms

    • Benign childhood epilepsy with centrotemporal EEG spikes
    • Childhood epilepsy with occipital EEG paroxysms

    Excludes1

    • adult onset localization-related epilepsy (G40.1-, G40.2-) G40.1 G40.2
  2. G40.00
    Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable
    Header
    Inclusion terms 1

    Inclusion terms

    • Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset without intractability
  3. G40.001
    Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, with status epilepticus
    BillableCC201
  4. G40.009
    Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, without status epilepticus
    BillableCC201
    Inclusion terms 1

    Inclusion terms

    • Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset NOS
  5. G40.01
    Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable
    Header
  6. G40.011
    Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, with status epilepticus
    BillableCC201
  7. G40.019
    Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, without status epilepticus
    BillableCC201
  8. G40.1
    Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures
    Header
    Inclusion terms 3

    Inclusion terms

    • Attacks without alteration of consciousness
    • Epilepsia partialis continua [Kozhevnikof]
    • Simple partial seizures developing into secondarily generalized seizures
  9. G40.10
    Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable
    Header
    Inclusion terms 1

    Inclusion terms

    • Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures without intractability
  10. G40.101
    Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, with status epilepticus
    BillableCC201
  11. G40.109
    Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, without status epilepticus
    BillableCC201
    Inclusion terms 1

    Inclusion terms

    • Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures NOS
  12. G40.11
    Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable
    Header
  13. G40.111
    Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable, with status epilepticus
    BillableCC201
  14. G40.119
    Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable, without status epilepticus
    BillableCC201
  15. G40.2
    Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures
    Header
    Inclusion terms 2

    Inclusion terms

    • Attacks with alteration of consciousness, often with automatisms
    • Complex partial seizures developing into secondarily generalized seizures
  16. G40.20
    Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable
    Header
    Inclusion terms 1

    Inclusion terms

    • Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures without intractability
  17. G40.201
    Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, with status epilepticus
    BillableCC201
  18. G40.209
    Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, without status epilepticus
    BillableCC201
    Inclusion terms 1

    Inclusion terms

    • Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures NOS
  19. G40.21
    Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable
    Header
  20. G40.211
    Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, with status epilepticus
    BillableCC201
  21. G40.219
    Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, without status epilepticus
    BillableCC201
  22. G40.3
    Generalized idiopathic epilepsy and epileptic syndromes
    Header
    Code also 1

    Code also

    • MERRF syndrome, if applicable (E88.42) E88.42
  23. G40.30
    Generalized idiopathic epilepsy and epileptic syndromes, not intractable
    Header
    Inclusion terms 1

    Inclusion terms

    • Generalized idiopathic epilepsy and epileptic syndromes without intractability
  24. G40.301
    Generalized idiopathic epilepsy and epileptic syndromes, not intractable, with status epilepticus
    BillableMCC201
  25. G40.309
    Generalized idiopathic epilepsy and epileptic syndromes, not intractable, without status epilepticus
    Billable201
    Inclusion terms 1

    Inclusion terms

    • Generalized idiopathic epilepsy and epileptic syndromes NOS
  26. G40.31
    Generalized idiopathic epilepsy and epileptic syndromes, intractable
    Header
  27. G40.311
    Generalized idiopathic epilepsy and epileptic syndromes, intractable, with status epilepticus
    BillableMCC201
  28. G40.319
    Generalized idiopathic epilepsy and epileptic syndromes, intractable, without status epilepticus
    BillableMCC201
  29. G40.A
    Absence epileptic syndrome
    Header
    Inclusion terms 3

    Inclusion terms

    • Childhood absence epilepsy [pyknolepsy]
    • Juvenile absence epilepsy
    • Absence epileptic syndrome, NOS
  30. G40.A0
    Absence epileptic syndrome, not intractable
    Header
  31. G40.A01
    Absence epileptic syndrome, not intractable, with status epilepticus
    Billable201
  32. G40.A09
    Absence epileptic syndrome, not intractable, without status epilepticus
    Billable201
  33. G40.A1
    Absence epileptic syndrome, intractable
    Header
  34. G40.A11
    Absence epileptic syndrome, intractable, with status epilepticus
    BillableCC201
  35. G40.A19
    Absence epileptic syndrome, intractable, without status epilepticus
    BillableCC201
  36. G40.B
    Juvenile myoclonic epilepsy [impulsive petit mal]
    Header
  37. G40.B0
    Juvenile myoclonic epilepsy, not intractable
    Header
  38. G40.B01
    Juvenile myoclonic epilepsy, not intractable, with status epilepticus
    BillableCC201
  39. G40.B09
    Juvenile myoclonic epilepsy, not intractable, without status epilepticus
    BillableCC201
  40. G40.B1
    Juvenile myoclonic epilepsy, intractable
    Header
  41. G40.B11
    Juvenile myoclonic epilepsy, intractable, with status epilepticus
    BillableCC201
  42. G40.B19
    Juvenile myoclonic epilepsy, intractable, without status epilepticus
    BillableCC201
  43. G40.C
    Lafora progressive myoclonus epilepsy
    Header
    Inclusion terms 1, Code also 1

    Inclusion terms

    • Lafora body disease

    Code also

    • , if applicable, associated conditions such as dementia (F02.8-) F02.8
  44. G40.C0
    Lafora progressive myoclonus epilepsy, not intractable
    Header
  45. G40.C01
    Lafora progressive myoclonus epilepsy, not intractable, with status epilepticus
    BillableCC201
  46. G40.C09
    Lafora progressive myoclonus epilepsy, not intractable, without status epilepticus
    BillableCC201
    Inclusion terms 1

    Inclusion terms

    • Lafora progressive myoclonus epilepsy NOS
  47. G40.C1
    Lafora progressive myoclonus epilepsy, intractable
    Header
  48. G40.C11
    Lafora progressive myoclonus epilepsy, intractable, with status epilepticus
    BillableCC201
  49. G40.C19
    Lafora progressive myoclonus epilepsy, intractable, without status epilepticus
    BillableCC201
  50. G40.4
    Other generalized epilepsy and epileptic syndromes
    Header
    Inclusion terms 10

    Inclusion terms

    • Epilepsy with grand mal seizures on awakening
    • Epilepsy with myoclonic absences
    • Epilepsy with myoclonic-astatic seizures
    • Grand mal seizure NOS
    • Nonspecific atonic epileptic seizures
    • Nonspecific clonic epileptic seizures
    • Nonspecific myoclonic epileptic seizures
    • Nonspecific tonic epileptic seizures
    • Nonspecific tonic-clonic epileptic seizures
    • Symptomatic early myoclonic encephalopathy
  51. G40.40
    Other generalized epilepsy and epileptic syndromes, not intractable
    Header
    Inclusion terms 2

    Inclusion terms

    • Other generalized epilepsy and epileptic syndromes without intractability
    • Other generalized epilepsy and epileptic syndromes NOS
  52. G40.401
    Other generalized epilepsy and epileptic syndromes, not intractable, with status epilepticus
    Billable201
  53. G40.409
    Other generalized epilepsy and epileptic syndromes, not intractable, without status epilepticus
    Billable201
  54. G40.41
    Other generalized epilepsy and epileptic syndromes, intractable
    Header
  55. G40.411
    Other generalized epilepsy and epileptic syndromes, intractable, with status epilepticus
    BillableCC201
  56. G40.419
    Other generalized epilepsy and epileptic syndromes, intractable, without status epilepticus
    BillableCC201
  57. G40.42
    Cyclin-Dependent Kinase-Like 5 Deficiency Disorder
    Billable201
    Inclusion terms 1, Use additional code 3

    Inclusion terms

    • CDKL5

    Use additional code

    • code, if known, to identify associated manifestations, such as:
    • cortical blindness (H47.61-) H47.61
    • global developmental delay (F88) F88
  58. G40.5
    Epileptic seizures related to external causes
    Header
    Inclusion terms 5, Use additional code 1, Code also 1

    Inclusion terms

    • Epileptic seizures related to alcohol
    • Epileptic seizures related to drugs
    • Epileptic seizures related to hormonal changes
    • Epileptic seizures related to sleep deprivation
    • Epileptic seizures related to stress

    Use additional code

    • code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5) T36 T50

    Code also

    • , if applicable, associated epilepsy and recurrent seizures (G40.-) G40
  59. G40.50
    Epileptic seizures related to external causes, not intractable
    Header
  60. G40.501
    Epileptic seizures related to external causes, not intractable, with status epilepticus
    BillableCC201
  61. G40.509
    Epileptic seizures related to external causes, not intractable, without status epilepticus
    BillableCC201
    Inclusion terms 1

    Inclusion terms

    • Epileptic seizures related to external causes, NOS
  62. G40.8
    Other epilepsy and recurrent seizures
    Header
    Inclusion terms 2

    Inclusion terms

    • Epilepsies and epileptic syndromes undetermined as to whether they are focal or generalized
    • Landau-Kleffner syndrome
  63. G40.80
    Other epilepsy
    Header
  64. G40.801
    Other epilepsy, not intractable, with status epilepticus
    BillableCC201
    Inclusion terms 1

    Inclusion terms

    • Other epilepsy without intractability with status epilepticus
  65. G40.802
    Other epilepsy, not intractable, without status epilepticus
    BillableCC201
    Inclusion terms 2

    Inclusion terms

    • Other epilepsy NOS
    • Other epilepsy without intractability without status epilepticus
  66. G40.803
    Other epilepsy, intractable, with status epilepticus
    BillableCC201
  67. G40.804
    Other epilepsy, intractable, without status epilepticus
    BillableCC201
  68. G40.81
    Lennox-Gastaut syndrome
    Header
  69. G40.811
    Lennox-Gastaut syndrome, not intractable, with status epilepticus
    BillableCC201
  70. G40.812
    Lennox-Gastaut syndrome, not intractable, without status epilepticus
    BillableCC201
  71. G40.813
    Lennox-Gastaut syndrome, intractable, with status epilepticus
    BillableCC201
  72. G40.814
    Lennox-Gastaut syndrome, intractable, without status epilepticus
    BillableCC201
  73. G40.82
    Epileptic spasms
    Header
    Inclusion terms 3

    Inclusion terms

    • Infantile spasms
    • Salaam attacks
    • West's syndrome
  74. G40.821
    Epileptic spasms, not intractable, with status epilepticus
    BillableCC201
  75. G40.822
    Epileptic spasms, not intractable, without status epilepticus
    BillableCC201
  76. G40.823
    Epileptic spasms, intractable, with status epilepticus
    BillableCC201
  77. G40.824
    Epileptic spasms, intractable, without status epilepticus
    BillableCC201
  78. G40.83
    Dravet syndrome
    Header
    Inclusion terms 2

    Inclusion terms

    • Polymorphic epilepsy in infancy (PMEI)
    • Severe myoclonic epilepsy in infancy (SMEI)
  79. G40.833
    Dravet syndrome, intractable, with status epilepticus
    BillableCC201
  80. G40.834
    Dravet syndrome, intractable, without status epilepticus
    BillableCC201
    Inclusion terms 1

    Inclusion terms

    • Dravet syndrome NOS
  81. G40.84
    KCNQ2-related epilepsy
    Header
  82. G40.841
    KCNQ2-related epilepsy, not intractable, with status epilepticus
    BillableCC201
  83. G40.842
    KCNQ2-related epilepsy, not intractable, without status epilepticus
    BillableCC201
    Inclusion terms 1

    Inclusion terms

    • KCNQ2-related epilepsy NOS
  84. G40.843
    KCNQ2-related epilepsy, intractable, with status epilepticus
    BillableCC201
  85. G40.844
    KCNQ2-related epilepsy, intractable, without status epilepticus
    BillableCC201
  86. G40.89
    Other seizures
    BillableCC201
    Excludes1 3

    Excludes1

    • post traumatic seizures (R56.1) R56.1
    • recurrent seizures NOS (G40.909) G40.909
    • seizure NOS (R56.9) R56.9
  87. G40.9
    Epilepsy, unspecified
    Header
  88. G40.90
    Epilepsy, unspecified, not intractable
    Header
    Inclusion terms 1

    Inclusion terms

    • Epilepsy, unspecified, without intractability
  89. G40.901
    Epilepsy, unspecified, not intractable, with status epilepticus
    Billable201
  90. G40.909
    Epilepsy, unspecified, not intractable, without status epilepticus
    Billable201
    Inclusion terms 6

    Inclusion terms

    • Epilepsy NOS
    • Epileptic convulsions NOS
    • Epileptic fits NOS
    • Epileptic seizures NOS
    • Recurrent seizures NOS
    • Seizure disorder NOS
  91. G40.91
    Epilepsy, unspecified, intractable
    Header
    Inclusion terms 1

    Inclusion terms

    • Intractable seizure disorder NOS
  92. G40.911
    Epilepsy, unspecified, intractable, with status epilepticus
    BillableCC201
  93. G40.919
    Epilepsy, unspecified, intractable, without status epilepticus
    BillableCC201

CC/MCC: as a secondary diagnosis, unless the principal diagnosis is on the code’s PDX exclusion list (MS-DRG v44 Appendix C; list on the code card).

Sources of each column.

Instructions

At G40

Notes

  • the following terms are to be considered equivalent to intractable: pharmacoresistant (pharmacologically resistant), treatment resistant, refractory (medically) and poorly controlled

Excludes1

  • conversion disorder with seizures (F44.5) F44.5
  • convulsions NOS (R56.9) R56.9
  • post traumatic seizures (R56.1) R56.1
  • seizure (convulsive) NOS (R56.9) R56.9
  • seizure of newborn (P90) P90

Excludes2

  • hippocampal sclerosis (G93.81) G93.81
  • mesial temporal sclerosis (G93.81) G93.81
  • temporal sclerosis (G93.81) G93.81
  • Todd's paralysis (G83.84) G83.84

Notes that also apply

Chapter 6 instructions (Excludes2 8): printed on the chapter 6 page.

Index entries

  • Epilepsia partialis continua → G40.1-
  • Kozhevnikof's epilepsy → G40.109
  • Pyknolepsy → G40.A09
  • Lafora disease → G40.C09
  • CDKL5 (Cyclin-Dependent Kinase-Like 5 Deficiency Disorder) → G40.42
  • Lennox-Gastaut syndrome → G40.812
  • PMEI (polymorphic epilepsy in infancy) → G40.83-
  • SMEI (severe myoclonic epilepsy in infancy) → G40.83-
  • Epilepsy, epileptic, epilepsia (attack) (cerebral) (convulsion) (fit) (seizure) → G40.909
  • Epilepsy, epileptic, epilepsia (attack) (cerebral) (convulsion) (fit) (seizure)partialis continua → G40.1-
  • Kozhevnikof's epilepsynot intractable → G40.109
  • Kozhevnikof's epilepsyintractable → G40.119
  • Seizure(s)absence → G40.A-
  • Seizure(s)petit mal → G40.A-
  • Epilepsy, epileptic, epilepsia (attack) (cerebral) (convulsion) (fit) (seizure)juvenile absence → G40.A09
  • Pyknolepsynot intractable → G40.A09
  • Pyknolepsyintractable → G40.A19
  • Epilepsy, epileptic, epilepsia (attack) (cerebral) (convulsion) (fit) (seizure)juvenile myoclonic → G40.B09
  • Disease, diseasedLafora body → G40.C09
  • Epilepsy, epileptic, epilepsia (attack) (cerebral) (convulsion) (fit) (seizure)Lafora progressive myoclonus → G40.C09
  • Myoclonus, myoclonic, myoclonia (familial) (essential) (multifocal) (simplex)epilepsy → G40.4-
  • Myoclonus, myoclonic, myoclonia (familial) (essential) (multifocal) (simplex)epileptica → G40.409
  • Seizure(s)grand mal → G40.409
  • Disorder (of)Cyclin-Dependent Kinase-Like 5 Deficiency (CDKL5) → G40.42
  • Epilepsy, epileptic, epilepsia (attack) (cerebral) (convulsion) (fit) (seizure)benign myoclonic in infancy → G40.80-
  • Epilepsy, epileptic, epilepsia (attack) (cerebral) (convulsion) (fit) (seizure)specified NEC → G40.802
  • Lennox-Gastaut syndromenot intractable → G40.812
  • SyndromeLennox-Gastaut → G40.812
  • Lennox-Gastaut syndromeintractable → G40.814
  • Epilepsy, epileptic, epilepsia (attack) (cerebral) (convulsion) (fit) (seizure)spasms → G40.822
  • Epilepsy, epileptic, epilepsia (attack) (cerebral) (convulsion) (fit) (seizure)polymorphic, in infancy (PMEI) → G40.83-
  • SyndromeDravet (intractable) → G40.834
  • Epilepsy, epileptic, epilepsia (attack) (cerebral) (convulsion) (fit) (seizure)KCNQ2-related → G40.842
  • Seizure(s)specified NEC → G40.89
  • Status (post)epileptic, epilepticus → G40.901
  • Disorder (of)seizure → G40.909
  • Epilepsy, epileptic, epilepsia (attack) (cerebral) (convulsion) (fit) (seizure)not intractable → G40.909
  • Seizure(s)disorder → G40.909
  • Seizure(s)recurrent → G40.909
  • Epilepsy, epileptic, epilepsia (attack) (cerebral) (convulsion) (fit) (seizure)intractable → G40.919

203 more, longer entries are not listed; the search box finds them by word.

NCHS Alphabetic Index. Index first, then the Tabular List.

Hierarchy