ICD-10-CM 2027
ICD-10 code for Arteriosclerotic parkinsonism
From the official ICD-10-CM alphabetic index entry “Parkinsonism (idiopathic) (primary) › arteriosclerotic”. Page updated September 29, 2026.
About coding Arteriosclerotic parkinsonism
The ICD-10-CM code for Arteriosclerotic parkinsonism is G21.4 (Vascular parkinsonism).
Within G21 (secondary parkinsonism), G21.4 is specifically for vascular parkinsonism. Related codes cover malignant neuroleptic syndrome (G21.0), other drug-induced secondary parkinsonism (G21.1), due to other external agents (G21.2), Postencephalitic parkinsonism (G21.3), other secondary parkinsonism (G21.8) and unspecified (G21.9).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 056 (Degenerative Nervous System Disorders with MCC, relative weight 2.2655) and DRG 057 (Degenerative Nervous System Disorders without MCC, relative weight 1.2838), in MDC 01 (Diseases and Disorders of the Nervous System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about Arteriosclerotic parkinsonism ICD-10 codes
What is the ICD-10 code for Arteriosclerotic parkinsonism?
- G21.4 — Vascular parkinsonism.
Is G21.4 billable?
- Yes. G21.4 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can G21.4 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict G21.4 as a principal diagnosis.
Is G21.4 a CC or MCC?
- No. G21.4 is neither a CC nor an MCC under MS-DRG v44.0.