G21
Non-billableSecondary parkinsonism
Secondary parkinsonism
This is a header/category code. For billing purposes, use a more specific child code from the list below.
Coding Notes
Excludes 1
Codes that cannot be used together with this code (mutual exclusion)
Excludes 2
Conditions not included here, but the patient may have both
- •certain conditions originating in the perinatal periodP04-P96
- •certain infectious and parasitic diseasesA00-B99
- •complications of pregnancy, childbirth and the puerperiumO9A)O00
- •congenital malformations, deformations, and chromosomal abnormalitiesQ00-Q99
- •endocrine, nutritional and metabolic diseasesE00-E88
- •injury, poisoning and certain other consequences of external causesS00-T88
- •neoplasmsC00-D49
- •symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classifiedR00-R94
Child Codes (7)
G21.0Malignant neuroleptic syndrome
G21.1Other drug-induced secondary parkinsonism
G21.2Secondary parkinsonism due to other external agents
G21.3Postencephalitic parkinsonism
G21.4Vascular parkinsonism
G21.8Other secondary parkinsonism
G21.9Secondary parkinsonism, unspecified
ICD-11 Equivalents(1)
ICD-11 Equivalents
View full mappingCorresponding ICD-11 codes from the WHO crosswalk mapping
Also Known As / Clinical Terms(24)
UMLS
- Disorders presenting primarily with parkinsonismC0030569
- PARKINSON DIS SECONDC0030569
- PARKINSON DIS SYMPTOMATICC0030569
- PARKINSONISM SECONDC0030569
- Parkinson Disease, SecondaryC0030569
- Parkinson Disease, SymptomaticC0030569
- Parkinsonism, SecondaryC0030569
- Parkinsonism, SymptomaticC0030569
- SECOND PARKINSONISMC0030569
- SYMPTOMATIC PARKINSON DISC0030569
- Secondary Parkinson DiseaseC0030569
- Secondary Parkinson diseaseC0030569
- Secondary Parkinson's diseaseC0030569
- Secondary ParkinsonismC0030569
- Secondary parkinsonismC0030569
- Secondary parkinsonism (disorder)C0030569
- Secondary parkinsonism, unspecifiedC0030569
- Symptomatic Parkinson DiseaseC0030569
- Symptomatic ParkinsonismC0030569
- Symptomatic parkinsonismC0030569
- Symptomatic parkinsonism (disorder)C0030569
- parkinson's disease secondaryC0030569
- parkinsonism secondaryC0030569
- secondary parkinsonismC0030569
Frequently Asked Questions
What is the ICD-10 code for secondary parkinsonism?
The ICD-10-CM code for secondary parkinsonism is G21. The full clinical description is "Secondary parkinsonism". G21 is a non-billable header code. Use a more specific child code for billing purposes.
What does ICD-10 code G21 mean?
ICD-10-CM code G21 represents “Secondary parkinsonism”. It is classified under Chapter 6: Diseases of the Nervous System and is a non-billable header code. Use a more specific child code for billing purposes.
Is G21 a billable code?
No, G21 is a non-billable header code. You need to use one of its more specific child codes for billing. There are 7 child codes under G21.
What chapter is G21 in?
G21 is in Chapter 6: Diseases of the Nervous System (codes G00-G99).
What codes cannot be used with G21?
G21 has Excludes1 notes indicating codes that cannot be used together with it, including: Huntington's disease (G10); neurocognitive disorder with Lewy bodies (G31.83); Shy-Drager syndrome (G90.3); and 1 more.
What are the subcategories under G21?
G21 has 7 child codes, including: G21.0 (Malignant neuroleptic syndrome), G21.1 (Other drug-induced secondary parkinsonism), G21.2 (Secondary parkinsonism due to other external agents), G21.3 (Postencephalitic parkinsonism), and 3 more.
What are the UMLS CUIs for G21?
G21 is linked to 1 UMLS Concept Unique Identifier: C0030569. The UMLS (Unified Medical Language System) integrates multiple biomedical vocabularies maintained by the U.S. National Library of Medicine.
How does G21 relate to ICF functioning codes?
ICF (International Classification of Functioning, Disability and Health) codes describe how conditions like secondary parkinsonism affect a person's functioning — body functions, activities, participation, and environmental factors. AutoICD provides ICF Core Sets for 12+ conditions and can map clinical text to ICF categories automatically. Browse the ICF directory to explore functioning codes.
What is the ICD-11 equivalent of G21?
G21 maps to the ICD-11 code: 8A00.2Z (Secondary parkinsonism, unspecified).
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Includes SNOMED Clinical Terms® (SNOMED CT®) used by permission of SNOMED International. Includes content from the UMLS Metathesaurus, courtesy of the U.S. National Library of Medicine.