ICD-10 Code G21.8 – Other secondary parkinsonism (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G21.8 – Other secondary parkinsonism
What it is
G21.8 identifies parkinsonism caused by another known condition, when the record does not fit a more specific secondary parkinsonism code. It covers Parkinson-like motor impairment that is secondary rather than idiopathic.
Clinical signs
Typical findings include bradykinesia, rigidity, tremor, and postural instability, but clinical features vary; refer to documentation. You should confirm the underlying cause and whether the provider describes a secondary parkinsonian syndrome.
When to use this code
Use this code when the provider documents secondary parkinsonism and the cause is not captured by a more specific ICD-10-CM option. It is appropriate when the chart describes Parkinson-like features due to another disorder, medication, or condition, and the documentation supports the secondary nature.
Do not use for
Do not use for idiopathic Parkinson disease or when a more specific secondary parkinsonism code is documented. Check documentation if the record only says “parkinsonism” without a clear secondary cause.
Coding tip
Always code the underlying condition first when the documentation identifies it, and use G21.8 only for the residual secondary parkinsonism.