ICD-10 Code G21.4 – Vascular Parkinsonism (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G21.4 – Vascular parkinsonism
What it is
G21.4 identifies parkinsonian symptoms caused by cerebrovascular disease. Use it when the chart documents vascular parkinsonism rather than idiopathic Parkinson disease.
Clinical signs
Typical findings include gait difficulty, lower-body predominance, rigidity, and slowed movement. Clinical features vary; refer to documentation, especially when imaging or stroke history supports a vascular cause.
When to use this code
Use G21.4 when the provider links parkinsonian features to prior strokes, small-vessel ischemic disease, or other vascular brain injury. It may be used when the record clearly distinguishes this condition from Parkinson disease or other secondary parkinsonism. Check documentation if the cause is not stated.
Do not use for
Do not use this code for idiopathic Parkinson disease, drug-induced parkinsonism, or unspecified tremor alone. If the record does not confirm a vascular cause, check documentation before assigning G21.4.
Coding tip
Code the documented vascular cause separately when supported, and avoid assuming G21.4 from gait problems alone.