ICD-10 Code G21.9 – Secondary parkinsonism, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G21.9 – Secondary parkinsonism, unspecified
What it is
G21.9 identifies parkinsonism caused by an underlying condition or exposure, when the specific cause is not documented. Use it for Parkinson-like movement problems without a more precise secondary parkinsonism type.
Clinical signs
Clinical features vary; refer to documentation. Typical findings include bradykinesia, rigidity, tremor, and postural instability, but the record should support a secondary, not idiopathic, parkinsonian syndrome.
When to use this code
Use this code when the provider documents secondary parkinsonism but does not specify the cause, such as drug-induced, vascular, or other named forms. It also fits when the chart confirms parkinsonism and the underlying etiology remains unclear. Check documentation for any more specific code.
Do not use for
Do not use G21.9 for primary Parkinson disease or for a more specific secondary parkinsonism code. If the cause is documented, code that condition instead.
Coding tip
Look for the exact documented cause of parkinsonism before assigning G21.9.