G21.1 – Other drug-induced secondary parkinsonism

ICD-10-CM 2027 diagnosis code · Extrapyramidal and movement disorders

Non-billable header

ICD-10-CM code G21.1

Code: G21.1 (claims format: G211)
Description: Other drug-induced secondary parkinsonism
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 6. Diseases of the nervous system (G00-G99)
Block: G20-G26 Extrapyramidal and movement disorders
Parent codes: G21

Billable codes under G21.1

G21.1 is a header code and cannot be used on claims. Choose the most specific code:

G21.11 – Neuroleptic induced parkinsonismBillable
G21.19 – Other drug induced secondary parkinsonismBillable

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

G21 – Secondary parkinsonism

Excludes1 (not coded here):

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

Related codes in G21

G21.0 – Malignant neuroleptic syndromeBillable
G21.2 – Secondary parkinsonism due to other external agentsBillable
G21.3 – Postencephalitic parkinsonismBillable
G21.4 – Vascular parkinsonismBillable
G21.8 – Other secondary parkinsonismBillable
G21.9 – Secondary parkinsonism, unspecifiedBillable

Frequently asked questions

What is ICD-10 code G21.1?

G21.1 is the ICD-10-CM code for other drug-induced secondary parkinsonism, in the block G20-G26 (Extrapyramidal and movement disorders).

Is G21.1 a billable code?

No. G21.1 is a header code with more specific child codes; report one of the billable codes listed above.

What category does G21.1 belong to?

It belongs to category G21 – Secondary parkinsonism.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.