ICD-10 Code G21.11 – Neuroleptic induced parkinsonism (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G21.11 – Neuroleptic induced parkinsonism
What it is
G21.11 identifies parkinsonian symptoms caused by neuroleptic, or antipsychotic, medication use. Use it when documentation links the movement disorder directly to the drug exposure.
Clinical signs
Typical findings include tremor, rigidity, bradykinesia, and masked facial expression. Clinical features vary; refer to documentation, especially when the record notes drug-induced parkinsonism or similar wording.
When to use this code
Use this code when the provider documents parkinsonism as a reaction to neuroleptic therapy. It is appropriate for encounters where the medication cause is stated clearly in the assessment or problem list. If the chart only mentions tremor or gait change without a cause, check documentation.
Do not use for
Do not use it for idiopathic Parkinson disease or for extrapyramidal symptoms without documented parkinsonism. Also avoid it when another cause of secondary parkinsonism is specified.
Coding tip
Link the diagnosis to the offending neuroleptic in the note whenever possible, and verify whether the provider describes the condition as drug induced.