G21.3
✓ Billable
Postencephalitic parkinsonism
ICD-10-CM · FY2026 · Diseases of the Nervous System
Code
G21.3
System
ICD-10-CM
Billable
Yes — valid for submission
Effective
FY2026
Chapter
Diseases of the Nervous System
Source
CMS / CDC NCHS
⚠ Verify before billing. Confirm against the current CMS/NCHS ICD-10-CM files and your payer's rules before claims submission.
Frequently asked questions
What is ICD-10 code G21.3?
ICD-10-CM code G21.3 represents Postencephalitic parkinsonism. It is a billable diagnosis code in the Diseases of the Nervous System chapter, effective October 1, 2025 – September 30, 2026.
Is G21.3 billable?
Yes. G21.3 is a valid billable ICD-10-CM code for insurance claims and clinical documentation.
What chapter is G21.3 in?
G21.3 belongs to the Diseases of the Nervous System chapter (G00–G99) of ICD-10-CM.
Related codes in the G21 category
G21
Secondary parkinsonism
Non-billable
G21.0
Malignant neuroleptic syndrome
Billable
G21.1
Other drug-induced secondary parkinsonism
Non-billable
G21.2
Secondary parkinsonism due to other external agents
Billable
G21.4
Vascular parkinsonism
Billable
G21.8
Other secondary parkinsonism
Billable
G21.9
Secondary parkinsonism, unspecified
Billable
G21.11
Neuroleptic induced parkinsonism
Billable
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