ICD-10 Code G20.A2 – Parkinson’s Disease Without Dyskinesia, With Fluctuations (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G20.A2 – Parkinson’s disease without dyskinesia, with fluctuations
What it is
This code identifies Parkinson’s disease with motor fluctuations but without dyskinesia. Use it when the chart documents Parkinson’s disease and “on-off” changes or wearing-off periods, and no dyskinesia is reported.
Clinical signs
Typical findings include bradykinesia, rigidity, tremor, and postural instability, with symptoms that vary during the day. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents Parkinson’s disease plus fluctuations in motor response to therapy, such as wearing off or unpredictable “off” periods. The record should also state that dyskinesia is absent. If the note only says Parkinson’s disease, check documentation for whether fluctuations are present.
Do not use for
Do not use this code if dyskinesia is documented; a different Parkinson’s code may apply. Do not assign it for tremor or gait problems alone without documented Parkinson’s disease.
Coding tip
Look for explicit wording like “with fluctuations” and “without dyskinesia” in the assessment or problem list.