ICD-10-CM Codes
G00-G99
G00-G09
G04-
2023 ICD-10-CM Diagnosis Code G04.02

2023 ICD-10-CM Diagnosis Code G04.02

Postimmunization acute disseminated encephalitis, myelitis and encephalomyelitis

2016

2017

2018

2019

2020

2021

2022

2023

Billable/Specific Code

G04.02 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
Short description: Postimmun ac dissem encphlts, myelitis and encephalomyelitis
The 2023 edition of ICD-10-CM G04.02 became effective on October 1, 2022.
This is the American ICD-10-CM version of G04.02 - other international versions of ICD-10 G04.02 may differ.

Applicable To

Encephalitis, post immunization
Encephalomyelitis, post immunization

Use Additional

Use Additional Help

Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation. In most cases the manifestation codes will have in the code title, "in diseases classified elsewhere." Codes with this title are a component of the etiology/manifestation convention. The code title indicates that it is a manifestation code. "In diseases classified elsewhere" codes are never permitted to be used as first listed or principle diagnosis codes. They must be used in conjunction with an underlying condition code and they must be listed following the underlying condition.

code to identify the vaccine (
ICD-10-CM Diagnosis Code T50.A
Poisoning by, adverse effect of and underdosing of bacterial vaccines
T50.A-
,
ICD-10-CM Diagnosis Code T50.B
Poisoning by, adverse effect of and underdosing of viral vaccines
T50.B-
,
ICD-10-CM Diagnosis Code T50.Z
Poisoning by, adverse effect of and underdosing of other vaccines and biological substances
T50.Z-
)

The following code(s) above G04.02 contain annotation back-references

Annotation Back-References

In this context, annotation back-references refer to codes that contain:

Applicable To annotations, or
Code Also annotations, or
Code First annotations, or
Excludes1 annotations, or
Excludes2 annotations, or
Includes annotations, or
Note annotations, or
Use Additional annotations

that may be applicable to G04.02:

G00-G99
2023 ICD-10-CM Range G00-G99
Diseases of the nervous system
Type 2 Excludes
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Diseases of the nervous system
G04
ICD-10-CM Diagnosis Code G04
Encephalitis, myelitis and encephalomyelitis
Includes
- acute ascending myelitis
- meningoencephalitis
- meningomyelitis
Type 1 Excludes
- encephalopathy NOS (G93.40)
Type 2 Excludes
- acute transverse myelitis (G37.3-)
- alcoholic encephalopathy (G31.2)
- multiple sclerosis (G35)
- myalgic encephalomyelitis (G93.32)
- subacute necrotizing myelitis (G37.4)
- toxic encephalitis (G92.8)
- toxic encephalopathy (G92.8)
Encephalitis, myelitis and encephalomyelitis
G04.0
ICD-10-CM Diagnosis Code G04.0
Acute disseminated encephalitis and encephalomyelitis (ADEM)
Type 1 Excludes
- acute necrotizing hemorrhagic encephalopathy (G04.3-)
- other noninfectious acute disseminated encephalomyelitis (noninfectious ADEM) (G04.81)
Acute disseminated encephalitis and encephalomyelitis (ADEM)

Approximate Synonyms

Encephalitis following immunization
Myelitis following immunization procedures
Post-immunization encephalitis
Post-immunization myelitis

ICD-10-CM G04.02 is grouped within Diagnostic Related Group(s) (MS-DRG v40.0):

023 Craniotomy with major device implant or acute complex cns principal diagnosis with mcc or chemotherapy implant or epilepsy with neurostimulator
024 Craniotomy with major device implant or acute complex cns principal diagnosis without mcc
097 Non-bacterial infection of nervous system except viral meningitis with mcc
098 Non-bacterial infection of nervous system except viral meningitis with cc
099 Non-bacterial infection of nervous system except viral meningitis without cc/mcc

Convert G04.02 to ICD-9-CM

Code History

2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
2017 (effective 10/1/2016): No change
2018 (effective 10/1/2017): No change
2019 (effective 10/1/2018): No change
2020 (effective 10/1/2019): No change
2021 (effective 10/1/2020): No change
2022 (effective 10/1/2021): No change
2023 (effective 10/1/2022): No change

Code annotations containing back-references to G04.02:

Type 2 Excludes: T88.1

ICD-10-CM Diagnosis Code T88.1
Other complications following immunization, not elsewhere classified
Applicable To
- Generalized vaccinia
- Rash following immunization
Type 1 Excludes
- vaccinia not from vaccine (B08.011)
Type 2 Excludes
- anaphylactic shock due to serum (T80.5-)
- other serum reactions (T80.6-)
- postimmunization arthropathy (M02.2)
- postimmunization encephalitis (G04.02)
- postimmunization fever (R50.83)

Diagnosis Index entries containing back-references to G04.02:

Complication(s) (from) (of)
- vaccination T88.1
  ICD-10-CM Diagnosis Code T88.1
  Other complications following immunization, not elsewhere classified
  2016 2017 2018 2019 2020 2021 2022 2023 Non-Billable/Non-Specific Code
  Applicable To
  Generalized vaccinia
  Rash following immunization
  Type 1 Excludes
  vaccinia not from vaccine (B08.011)
  Type 2 Excludes
  anaphylactic shock due to serum (T80.5-)
  other serum reactions (T80.6-)
  postimmunization arthropathy (M02.2)
  postimmunization encephalitis (G04.02)
  postimmunization fever (R50.83)
  - encephalitis or encephalomyelitis G04.02
  - myelitis G04.02
Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) G04.90
ICD-10-CM Diagnosis Code G04.90
Encephalitis and encephalomyelitis, unspecified
Applicable To
Ventriculitis (cerebral) NOS
- acute A86
  - see also Encephalitis, viral
  ICD-10-CM Diagnosis Code A86
  Unspecified viral encephalitis
  2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
  Applicable To
  Viral encephalomyelitis NOS
  Viral meningoencephalitis NOS
  - disseminated G04.00
    ICD-10-CM Diagnosis Code G04.00
    Acute disseminated encephalitis and encephalomyelitis, unspecified
    2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
    - postimmunization G04.02 (postvaccination)
- due to
  - smallpox inoculation G04.02
- following vaccination or other immunization procedure G04.02
- postimmunization G04.02
- postvaccinal G04.02
Encephalomyelitis G04.90
- see also Encephalitis
ICD-10-CM Diagnosis Code G04.90
Encephalitis and encephalomyelitis, unspecified
Applicable To
Ventriculitis (cerebral) NOS
- acute disseminated G04.00
  ICD-10-CM Diagnosis Code G04.00
  Acute disseminated encephalitis and encephalomyelitis, unspecified
  2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
  - postimmunization G04.02
- postvaccinal G04.02
Encephalopathy (acute) G93.40
ICD-10-CM Diagnosis Code G93.40
Encephalopathy, unspecified
- in (due to) (with)
  - vaccination G04.02
Leukoencephalitis G04.81
ICD-10-CM Diagnosis Code G04.81
Other encephalitis and encephalomyelitis
Applicable To
Noninfectious acute disseminated encephalomyelitis (noninfectious ADEM)
- acute (subacute) G36.1
  ICD-10-CM Diagnosis Code G36.1
  Acute and subacute hemorrhagic leukoencephalitis [Hurst]
  2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
  - postimmunization or postvaccinal G04.02
Leukoencephalopathy G93.49
- see also Encephalopathy
ICD-10-CM Diagnosis Code G93.49
Other encephalopathy
Applicable To
Encephalopathy NEC
- postimmunization and postvaccinal G04.02
Meningoencephalomyelitis - see also Meningoencephalitis
- acute NEC (viral) A86
  ICD-10-CM Diagnosis Code A86
  Unspecified viral encephalitis
  2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
  Applicable To
  Viral encephalomyelitis NOS
  Viral meningoencephalitis NOS
  - disseminated G04.00
    ICD-10-CM Diagnosis Code G04.00
    Acute disseminated encephalitis and encephalomyelitis, unspecified
    2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
    - postimmunization or postvaccination G04.02
- postimmunization or postvaccination G04.02
Myelitis (acute) (ascending) (childhood) (chronic) (descending) (diffuse) (disseminated) (idiopathic) (pressure) (progressive) (spinal cord) (subacute) G04.91
- see also Encephalitis
ICD-10-CM Diagnosis Code G04.91
Myelitis, unspecified
- postimmunization G04.02
- postvaccinal G04.02

ICD-10-CM Codes Adjacent To G04.02

G03 Meningitis due to other and unspecified causes

G03.0 Nonpyogenic meningitis

G03.1 Chronic meningitis

G03.2 Benign recurrent meningitis [Mollaret]

G03.8 Meningitis due to other specified causes

G03.9 Meningitis, unspecified

G04 Encephalitis, myelitis and encephalomyelitis

G04.0 Acute disseminated encephalitis and encephalomyelitis (ADEM)

G04.00 Acute disseminated encephalitis and encephalomyelitis, unspecified

G04.01 Postinfectious acute disseminated encephalitis and encephalomyelitis (postinfectious ADEM)

G04.02 Postimmunization acute disseminated encephalitis, myelitis and encephalomyelitis

G04.1 Tropical spastic paraplegia

G04.2 Bacterial meningoencephalitis and meningomyelitis, not elsewhere classified

G04.3 Acute necrotizing hemorrhagic encephalopathy

G04.30 …… unspecified

G04.31 Postinfectious acute necrotizing hemorrhagic encephalopathy

G04.32 Postimmunization acute necrotizing hemorrhagic encephalopathy

G04.39 Other acute necrotizing hemorrhagic encephalopathy

G04.8 Other encephalitis, myelitis and encephalomyelitis

G04.81 Other encephalitis and encephalomyelitis

G04.82 Acute flaccid myelitis

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.

2023 ICD-10-CM Diagnosis Code G04.02

Postimmunization acute disseminated encephalitis, myelitis and encephalomyelitis

Poisoning by, adverse effect of and underdosing of bacterial vaccines

Poisoning by, adverse effect of and underdosing of viral vaccines

Poisoning by, adverse effect of and underdosing of other vaccines and biological substances

Diseases of the nervous system

Encephalitis, myelitis and encephalomyelitis

Acute disseminated encephalitis and encephalomyelitis (ADEM)

Other complications following immunization, not elsewhere classified

Other complications following immunization, not elsewhere classified

Encephalitis and encephalomyelitis, unspecified

Unspecified viral encephalitis

Acute disseminated encephalitis and encephalomyelitis, unspecified

Encephalitis and encephalomyelitis, unspecified

Acute disseminated encephalitis and encephalomyelitis, unspecified

Encephalopathy, unspecified

Other encephalitis and encephalomyelitis

Acute and subacute hemorrhagic leukoencephalitis [Hurst]

Other encephalopathy

Unspecified viral encephalitis

Acute disseminated encephalitis and encephalomyelitis, unspecified

Myelitis, unspecified