ICD-10 Code G20 – Parkinson’s disease (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G20 – Parkinson’s disease
What it is
G20 identifies Parkinson’s disease, a chronic neurodegenerative disorder that mainly affects movement. Use it for documented Parkinson’s disease, not for symptoms alone or other parkinsonian syndromes.
Clinical signs
Typical features include bradykinesia, resting tremor, rigidity, and postural instability. Clinical features vary; refer to documentation, especially when the record distinguishes Parkinson’s disease from secondary or atypical parkinsonism.
When to use this code
Use G20 when the provider documents Parkinson’s disease as the diagnosis, whether newly recognized or established. It may also apply when follow-up care, medication management, or neurologic assessment is clearly tied to that diagnosis. Check documentation if the note only mentions tremor, gait change, or parkinsonism without a firm diagnosis.
Do not use for
Do not use G20 for drug-induced parkinsonism, secondary parkinsonism, or vague “parkinsonian features” without a confirmed diagnosis. Check documentation when the cause or specific syndrome is not stated.
Coding tip
Code the documented diagnosis, not isolated movement symptoms, and verify whether the provider means Parkinson’s disease or another parkinsonian disorder.