2026 ICD-10-CM Diagnosis Code G21Secondary parkinsonism
G21 is a non-billable ICD-10-CM category code for secondary parkinsonism, so it cannot be submitted on claims. Use a more specific code from this category instead, such as G21.0, G21.11, G21.19, and G21.2.
Code Identity
Code Classification
Specific Coding for Secondary parkinsonismOverview
Non-specific codes like G21 require more characters. Use one of these billable codes instead:
Use G21.0 for Malignant neuroleptic syndrome
G21.1 for Other drug-induced secondary parkinsonism
Use G21.11 for Neuroleptic induced parkinsonism
Use G21.19 for Other drug induced secondary parkinsonism
Use G21.2 for Secondary parkinsonism due to other external agents
Use G21.3 for Postencephalitic parkinsonism
Use G21.4 for Vascular parkinsonism
Use G21.8 for Other secondary parkinsonism
Use G21.9 for Secondary parkinsonism, unspecified
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Type 1 Excludes
- Huntington's disease G10
- neurocognitive disorder with Lewy bodies G31.83
- Shy-Drager syndrome G90.3
- syphilitic Parkinsonism A52.19
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Patient EducationClinical
Parkinson's Disease
Parkinson's disease (PD) is a type of movement disorder. It happens when nerve cells in the brain don't produce enough of a brain chemical called dopamine. Sometimes it is genetic, but most cases do not seem to run in families. Exposure to chemicals in the environment might play a role.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
