Is G21.11 a billable ICD-10-CM code?

Yes. G21.11 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does G21.11 sit in the tabular list?

Diseases of the nervous system (G00-G99), in the block Extrapyramidal and movement disorders (G20-G26).

What cannot be coded together with G21.11?

G21.11 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

G21.11

G21.11 — Neuroleptic induced parkinsonism

Billable / specific codeICD-10-CM

G21.11 is a billable, specific ICD-10-CM code for neuroleptic induced parkinsonism. It is valid for submission on a claim.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

malignant neuroleptic syndrome (G21.0)

Use additional code

Add a secondary code to capture the detail described below.

code for adverse effect, if applicable, to identify drug (T43.3X5, T43.4X5, T43.505, T43.595)

Other codes that can never be billed with G21.11

These codes carry an Excludes1 note pointing at G21.11. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading G21.11 alone.

G21.0Malignant neuroleptic syndrome

Risk adjustment

G21.11 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

G21.11 is named in 12 Medicare coverage policies — 12 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A54111Billing and Coding: Speech Language Pathology (SLP) Services: Communication Disorders
A56612Billing and Coding: CT of the Head
A56619Billing and Coding: Nerve Conduction Studies and Electromyography
A56621Billing and Coding: Swallowing Studies for Dysphagia

How G21.11 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to G21.11.

Parkinsonism›neuroleptic induced
Parkinsonism›due to›drugs NEC›neuroleptic
Parkinsonism›secondary›due to›drugs NEC›neuroleptic

Related codes at this level

Codes that share G21.1. If G21.11 is not quite right, the correct code is usually one of these.

G21.19Other drug induced secondary parkinsonism

Questions about G21.11

Is G21.11 a billable ICD-10-CM code?: Yes. G21.11 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does G21.11 sit in the tabular list?: Diseases of the nervous system (G00-G99), in the block Extrapyramidal and movement disorders (G20-G26).
What cannot be coded together with G21.11?: G21.11 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.