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G21

Non-billable

Secondary parkinsonism

G21 is the ICD-10-CM code for Secondary parkinsonism. It is a non-billable category code — use a more specific child code such as G21.0 for billing.

Status
Header (non-billable)
Chapter
G00-G99
Subcodes
7
Edition
FY2026

G00-G99 Diseases of the nervous system

Excludes1 — not coded here

  • •Huntington's disease (G10)
  • •neurocognitive disorder with Lewy bodies (G31.83)
  • •Shy-Drager syndrome (G90.3)
  • •syphilitic Parkinsonism (A52.19)

Frequently asked questions

What is ICD-10 code G21?
G21 is the ICD-10-CM code for "Secondary parkinsonism". It falls under G00-G99 Diseases of the nervous system.
Is G21 a billable code?
No — G21 is a non-billable header code. Use a more specific child code (such as G21.0) for billing.
What are the subcodes of G21?
G21 has 7 more specific child codes, including G21.0, G21.1, G21.2.
What is excluded from G21?
Excludes1 (not coded here): Huntington's disease (G10); neurocognitive disorder with Lewy bodies (G31.83); Shy-Drager syndrome (G90.3); syphilitic Parkinsonism (A52.19).

Source: CMS ICD-10-CM FY2026. For informational purposes only — not medical advice. See our medical disclaimer.

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