ICD-10 Code G20.A1 – Parkinson’s disease without dyskinesia, without mention of fluctuations (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G20.A1 – Parkinson’s disease without dyskinesia, without mention of fluctuations
What it is
This code identifies Parkinson’s disease when the record does not mention dyskinesia or motor fluctuations. Use it for documented Parkinson’s disease without those specific complications.
Clinical signs
Typical findings include bradykinesia, resting tremor, rigidity, and postural instability. Clinical features vary; refer to documentation.
When to use this code
Assign this code when the provider documents Parkinson’s disease and specifically states no dyskinesia and no fluctuations, or omits both complications in a way that supports this code. Use the diagnosis as recorded in the chart, not your assumptions.
Do not use for
Do not use it if dyskinesia or motor fluctuations are documented. Check documentation if the note describes a different parkinsonian disorder or does not clearly support Parkinson’s disease.
Coding tip
Match the code to the exact complication status in the provider’s note before finalizing.