G21.0

ICD-10Billable

Malignant neuroleptic syndrome

Official ICD-10-CM descriptor (FY2026)

Malignant neuroleptic syndrome

G21.0 is valid for submission on a claim — CMS flags it as a billable, specific code.

Excludes1

Not coded here. An Excludes1 code should never be reported at the same time as the code above it.

  • neuroleptic induced parkinsonism (G21.11)

Use additional code

Report an additional code to identify the associated condition.

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

Related codes in G21

Where this code sits

Parent code
G21

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Source

ICD-10-CM FY2026. Centers for Medicare & Medicaid Services (CMS) / National Center for Health Statistics (NCHS), “2026 ICD-10-CM Code Descriptions in Tabular Order” (icd10cm_order_2026.txt). Download the original file from cms.gov. Public domain (US Government work). Descriptors, billable flags and instructional notes on this page are reproduced from that file without modification. Krasyn adds no clinical guidance.

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