G21.0 vs G21.11
G21.0 (Malignant neuroleptic syndrome) compared with G21.11 (Neuroleptic induced parkinsonism), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. G21.0 carries an Excludes1 note covering G21.11: “neuroleptic induced parkinsonism (G21.11)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
No — do not report together. G21.11 carries an Excludes1 note covering G21.0: “malignant neuroleptic syndrome (G21.0)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| G21.0Malignant neuroleptic syndrome | G21.11Neuroleptic induced parkinsonism | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | G00-G99 — Diseases of the Nervous System (G00-G99) | G00-G99 — Diseases of the Nervous System (G00-G99) |
| Definition | Malignant neuroleptic syndrome is a billable ICD-10-CM diagnosis code (G21.0). | Neuroleptic induced parkinsonism is a billable ICD-10-CM diagnosis code (G21.11). |
| Use additional code | code for adverse effect, if applicable, to identify drug (T43.3X5, T43.4X5, T43.505, T43.595) | code for adverse effect, if applicable, to identify drug (T43.3X5, T43.4X5, T43.505, T43.595) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources